Half-Life Opposing Force FAQ/Walkthrough For PC Table of Contents: 1. Copyright 2. Intro 3. Walkthrough 4. FAQS 5. Contact info 6. Thanks ==================================== 1. Copyright This Guide is Copyright 2005 InfernalColonel. This guide may not be reproduced on any other website unless by my permission or the permission of GameFaqs.com This guide on any other web site or as a part of any public display is Strictly prohibited, and a violation of copyright. ==================================== 2. Intro Welcome to the Black Mesa Re... I mean my guide. Being a huge fan of the Half-life series I decided to write a guide. Since Opposing Force is my favorite game, and Adrian Shepard is my favorite character, I... well fill in the blanks. But enough talk, get moving soldier! ==================================== 3. Walkthrough A mysterious job to an unknown place, what could go wrong? Just enjoy the ride, that is until the copter crashes. "Welcome to Black Mesa" After you wake up talk to the scientist and leave the room. In the next hallway make your first left and go through the double door. You will see two scientists carrying a wounded soldier. Go straight forward until you reach the room with the dead soldiers. Grab your armor on the table and head back to where you saw the two scientists. Head left this time. You will see a scientist and a mawman. The mawman will kill the scientist and escape. So just continue forward until you see a security guard kill a mawman. Talk to him and he will open the security door. In this next hallway watch out for the hanging wire and grab the wrench to the right of it. Continue forward and crouch under the green laser, then crouch under the purple laser near the staircase. Jump on the metal gratings and jump over the green laser. Now jump over the green laser and destroy the mirror that’s aiming the purple laser. After the explosion, go up the staircase and exit the room. Go through the hallway and kill the two headcrabs that drop down. In the room with the radioactive waste containers jump over the waste blocking your path and kill the headcrab on the other side. Go to the security door in the next room you will see the G-man talking to a security guard. Go up the staircase and through the door. In this small hallway break all the boxes in back. Grab the medkit and go through the metal door. Outside at last! You will see a broken bridge. Jump on the grassy part below it and follow this little path. When you reach the top, turn left and jump to the other side. Grab the knife by the dead vortigon, go left and grab the medkit. After you grabbed it go back and turn left. Jump across the broken bridge and go through the open door. Equip your night vision and kill the headcrab in front of you. Crawl through the hole on the right side and go forward until you reach the end. Go straight forward until you reach the downed helicopter. Go through the open blast door on your right and kill the three headcrabs that come out of the hole in the wall. Continue through the tunnel until you reach the electrified fence. After the security guard tries to climb it go through the open vent right next to the fence. Crawl through the vent until you reach the giant fan. Keep going right when the electricity stops and crawl through the open vent at the end. Just go through the vent and stop when you reach the electrical generators. Go right and walk to the security guard. Don't touch the fence or you will be electrocuted. Grab the gun by the dead security guard and run forward when the electricity stops. Go to the generator control and flip the switch. Go through the door the security guard tried to climb and head back through the blast door. When you get near the hole in the wall a vortigon will appear behind you. So kill him and continue forward. Kill the vortigon near the end and walk up to the downed helicopter. Walk forward and grab the health and armor by the dead soldier then climb the ladder down near the two sewer holes. Put on your night vision and climb down the other ladder. When your at the broken ladder, jump down and step onto the metal grating. Watch out for the barnacles and walk across the metal grating until you reach the end. Go left and through the door. Now just walk across the bridge and go through the metal door. Kill the vortigon and grab the shotgun by the dead soldier. Walk across the metal grating and kill the vortigon at the bottom. Just avoid the steam and walk on the metal grating until you reach the ladder. Climb down the ladder and kill the vortigon at the bottom. Walk across the metal grating and go through the security door. In the next room jump down and kill the two vortigons. Smash the two boxes, grab the health and armor and go through the hallway to your left. In the room with the radioactive waste jump across and stay to the right of the red security door. After the explosions immediately jump on the busted grating and walk across the top until the G-man opens the security door. Go through this hallway and take the elevator down. In the room with the waste, jump across and kill the four headcrabs behind the boxes. Go up the staircase and kill the two headcrabs. Use the first-aid station and hit the switch. Position the panel until the box carrier is near the left wall. Head back, climb on boxes and jump on the box carrier. Now jump on the boxes on the left wall, grab the armor and hit the switch. Go back to the controls and position the carrier so its directly in front of the opened security door. Jump back on the carrier and kill the headcrab on the box to the right of you. After its dead, jump on the box, and jump into the hallway. Go through and hit the switch on the cross signs to lift them up. Go to the end where the wall has collapsed and head right through the busted wall. Jump in the pipe and let the stream carry you away. When you reach the bottom, go through the broken grating. Avoid the barnacles and make your first right. Now just avoid the barnacles and go forward until you reach the ladder on the right wall. Climb up the ladder and go through the narrow hallway. If a barnacle grabs you, knife him when your towards his body. Go across the metal grating and grab the ammo and grenades on the right side. Go forward through the hallway until you reach the door. In this next room with the waste, shoot the explosive crates by the yellow robot and wait until he leaves the room. After he opens the ladders, climb down the ladder at the end and jump across the boxes to the sewage overflow controls. Drain the waste and hit the switch near the door on the left side. Take the elevator up and at the top, kill the four dogs. Walk up the ramp and jump into the freight car. "We are pulling out" Enjoy your ride in the transit car. Kill any vortigons you see that are charging up their shots. When the car stops, get out and grab the guns and ammo in front of you. Then turn around and kill the two vortigons. Enter the hallway and talk to the guard by the vending machine. A mawman is behind the the door, so let the guard kill him. Now have him follow you, he's a great shot. Go up the stairs and kill the two headcrabs and mawmen. Go up the next flight of stairs and kill the two dogs and the vortigon that appears. Now watch the glass as the shocker kill the security guards and takes the scientist. After he disappears jump through the glass and leave the room. Kill the two headcrabs and take the elevator up. Kill the three vortigons at the top charge your suit, and break the boxes in the room to get ammo. Jump on the green boxes and on the HEV charger. Now break the case and go through the vent. At the end of the vent, climb up the ladder to the top and crawl through the vent. A helicopter, finally you can leave. Go through the and grab the explosives and grenades in the next room. Go through the door and grab the ammo on the counter. Go to the room where the soldier is interrogating the scientist and grab the armor chargers on the top shelf. Now go down the stairs and follow the path to the helicopter. Your finally, oh no! The G-man will close the door, man what an unlucky day. Anyway, after the door closes go to the wall being broke down and kill the vortigon behind it. Two more vortigons will appear to your right and left, so kill them and go through the wall. "Missing in Action" Go left and walk across when the steam stops. Now crouch and crawl under the blue pipe. Kill the headcrab on the other side and head right. Kill the two vortigons that appear and grab the ammo on the green boxes. Smash the boxes in the room to get some health then climb up the three blue pipes and crawl through the vent. Crawl through the vent until you reach the second case and drop down. Grab the health and ammo on the shelfs and exit the room. Okay rinse and repeat. Go back to the pipes, go through the vent and this time break the first case. Walk through the passageway. You see those darkended tiles? If you step on them you will drop down and lose some health so don't step on them. Instead of going down the broken vent continue forward and jump over the darkened tiles. Your near the fans. Step on the thin covers on the fans and walk across until you reach the end. Drop dwon on the metal grating and walk across when the steam stops, then crawl under the steam in front of you. Now go to the fans and walk across the metal grating. Drop down and go through the hole in the floor by the broken fan to your right. Drop down and break the case in the window vent. Jump across when the fire stops. On the next platform shoot the headcrab on the other side and jump across. Look to your right and kill the big mawman. Head right and go through the wooden vent. Break the case at the end and walk across when the fire stops. At the second flame shooter when the flames stop head left through the tube and jump up. Kill the two big mawmen and the two regular mawmen when you get up. You will see a little Xen like area here, so grab the grenade and push the explosive crate into the small metal tunnel where it has a warning sign. Head up and activate the test fire. After the explosion, drop down through the hole in the floor. Kill the big mawman at the bottom and the three headcrabs. Just walk forward until you reach the broken vent. Kill the headcrab in it, crawl through it, and head left. Break the case at the end and drop down. Go down the pavement and talk to the dying soldier by the truck. Walk forward and head left to storage area 2. Break the box next to the one that says "fragile" to get some health. Hit the switch to open the red door to your right and kill the four pit drones. Head up the stairs and grab the charger to your left. Where the sign says "service elevator" head up the stairs and kill the two pit drones. Don't worry about the scientist behind the table, just go left through the open elevator door. Instead of explaining everything just head down until you reach the crashed elevator cart. Go into it, climb up, and enter the room. Head left and slide around the hanging electrical wire. Jump on the green boxes, head left and flip the switch on the unit 2 power. Leave the room and head back to the crashed elevator cart. This time, climb to the very top to the warning sign, then jump on and climb the rope in front of you. Climb up until you see the hanging elevator cart and jump in it. Grab the two chargers inside, climb up, and enter the hallway. Head left and push the small metal crate in front of the vent. Crawl through the vent until the explosion and step into the water. Turn around, kill the spitter and grab the ammo by the dead soldier. Step into the hallway and head right to the exit sign. Grab the metal crate again and push it up to the trashcan near the shelfs blocking your way. Jump over it and shoot the explosive in the room to your right. Grab the health pack behind the book shelfs and take the metal crate to the vent. Go through the vent and kill the headcrab. In the next room you will see a scientist being electrocuted, exit the room and drop into the hole where the floor tile is missing. Grab the chargers, flip the switch and climb up the rope above you. Grab the ammo near the dead scientist and guard and activate the radio. After the soldiers break down the door, get the engineer to open up the sealed door. Enter the elevator and take it up. "Friendly Fire" After the elevator stops, leave it and walk forward. Three vortigons will appear (two on bottom, one on top) so let the engineer take them out. Take him to the exit sign and let him cut through it. In the next room walk through the tunnel and grab the ammo and explosives in the security office. Head back to where you fought the vortigons and head up the stairs. When your near the door a vortigon will break it down, so kill him and enter the room. Now go through the room with the broken door and kill the two vortigons. Grab the ammo on S. Jones desk and grab the health on the file cabinets. Exit the room and go through the red door, then kill the three vortigons and the alien grunt that drop down. Enter the wooden double doors and kill the three vortigons in the next room. Exit through the hole in the wall and kill the two vortigons in the next hallway to your left. Walk forward and make your first left into a room that says "B-591FG." You will see picture of Freeman on the wall, but crouch under the broken pipes and head up. Jump on the vent and head up. Grab the charger by the dead scientist (but watch out for the barnacle) and head right. Climb up the ladder and jump on the metal grating. Jump across the broken bridge and enter the security door. In the next room, on the other side, two alien grunts will be firing at you. Shoot the explosive behind them and then destroy the electrical circuit to your left. Jump across to the other side using the purple wires. When your across break the boxes to your right to get some ammo and take the elevator up. Grab the ammo, health, and explosives in the next room and kill the two dogs comming towards you. Walk up this ramp and kill the dog. Climb up the broken piller until you reach the surface and talk to the medic. Turn around and head through the metal door. Throw a grenade in there to destroy the turret and walk through the hallway. Use your grenades to destroy the laser mines and walk through the door. Now head back and crawl through the broken vent directly in front of you. Head left and listen to the two guys talk. These are Black-ops YOUR clean up crew. Shoot the casing and kill the five Black-ops in this room. Head right and go through the rusty door by the switch. You will see a wounded engineer. Go back grab the medic, and have him heal the soldier. After he's healed have the engineer follow you to where you met the medic, and have him break down the door that has a secured access sign above it. He will run forward and die, but he will explode after he dies, destroying the turret. Grab the explosives by the green box, destroy the laser mines in the next room, and head down the stairs. Talk to the two soldiers and have them follow you forward. In this next room there are female Black-ops. They are quick and deadly so kill them and head up the stairs on the right wall. Pull and hold the switch and head back. The secure access door is open so head left, down the tracks. When you reach the room with the shelves break the box to get some health and head right. In the next hallway, kill the four black-ops and use the PC-V recharge unit in the small room. Just follow the path and kill any black-ops you see. In the area marked "Storage area 3" grab the health pack and charger in the room, go back, and head up the staircase.Pull and hold the switch and go all the way back to the transit car. When your on the transit car head backwards until you pass the red sign. Shoot the sign so that it points left and go forward. Just avoid the electrical wire and stay on the cart until you reach the secure access door. Shoot the black-op to your left and go through the broken window. Grab the RPG and all the ammo on the shelfs and push the crate next to the broken piller. Climb up the piller until you reach the top. Break through the casing and crawl through the vent. "We are not alone" In the next hallway, you will hear the scientist talking to Freeman. Turn left and hit the switch on the wall. In the room Freeman will be jumping through a portal. Don't go in that one, instead go around to where the staircase has fallen. Run up it and jump through the portal. Amazing, your in Xen. Jump on the platform to your left and grab the ammo carrier. Use the jumping pad to get to the high platform in front of you. A scientist will drop from the sky on to a platform in front of you. Jump on it and grab the portal gun by him. Jump on the next platform and use the jumping pad to get to the right of you. Kill the dogs, jump across and use the junmping pad to get to the next platform. Now when your at the top run and jump into the portal. "Crush Depth" Go up the elevator and hit the switch. Now take the elevator down. When you get off the elevator head left and go through the broken door. Go down the hallway until you reach the computers. Kill the two drones behind the desk, charge up your health and armor, and hit the yellow button. A scientist will teleport towards the opening, so have him follow you back to the elevator. This time head left and have him open the security door. Go through the door and kill the spitter. Grab the ammo to the right of him and have the scientist open the security door. After he dies, go back to the broken glass tank and climb up the ladder. Go up the ramp and kill the four drones, then grab the health pack. Head right and a drone will break down the wall. Kill the three drones on the other side and go through the vent. Break the casing and drop down. Grab the ammo on the right wall and enter the cage type thing. Hit the switch and after the explosions you will be warped into a water tank. Go through the area to your left and go up the ramp. Go down the hallway and kill the three mawmen and the two headcrabs. Go through the vent and drop down until your in the water. Go up the ladder and head down the hallway to where it says "Warning, hazardous machinery." Kill the two headcrabs, and mawmen and drop down. Kill the two mawmen, grab the health kit under the platform and charge up your armor. Head down the ladder and turn the valve. Go back to where you dropped into the water and go back in. The gate in front of you is now open but that means the ichthyosaur is too. Instead of fighting him, go through the opening and head to the door. Turn the valve to empty the water and go through the open gate. Grab the ammo by the dead soldier and go near the electricity. Shoot the electrical circuit behind it, walk forward and kill the two drones and the shock trooper that appear. After you kill the shock trooper grab his weapon and head left through the door. Go through the door, grab the ammo by the dead scientist and jump through the portal. On Xen jump into the portal right in front of you. Hit the swtich and go through the door. your gonna have to go under water and fight the two ichyosaurs. Use your portal gun to get rid of them quickly and head up the tube at the top of the wall. Break the casing and get out of the water. Now just walk forward to the biohazard sign. "Vicarious Reality" Go through this hallway and climb up the broken piller. When your at the top jump on the ledges on the wall. Shoot the headcrab directly in front of you and jump near the dead security guard. Grab the ammo near him and kill the headcrabs to the left and right room. Head right to the hall with the dead scientist and kill the headcrab near him. Head down this hall to the "specimen observation area 1" sign and head through the door. Go through the long hallway until you reach the door. Its locked so head back and kill the two pit drones and the shock trooper that appear. Jump through the broken glass into the observation area. Head towards the opening in the rocks and kill the voltigore that appears. Head through the door, and head up the lift. In this next room kill the three headcrabs and the big mawman. On the right side of the room open up the far right cage and pick up the spores inside. After you picked up the ammo turn around and go through the door near the "authorized personnel only" sign. Just go directly forward to the broken elevator, break the glass and jump inside. Climb up the open shaft and when on top climb the long yellow ladder. At the top, jump off onto the broken door and enter this hallway. Make a left at the "authorized personnel only" sign and enter the door. Just look at the giant Xen like area and go through the door. Although this looks like the same area, its not. Make a left and enter the elevator. Take the elevator down, head right at the broken pillers and enter the control room. Kill the three pit drones in this room and head up the ramp where the dead scientist is. Grab the charger on the table and break the glass. Go down the ramp in this Xen area and kill the four dogs and the spitter. Step in the healing pool and head through the door to the left of it. Head up the lift and in the next room, grab the spore launcher by the broken tank. Head left and go straight forward. Kill the big mawman, break the tank to get the spores and head through the door. Head left at the "specimen observation area 2" sign and go through the door. Follow the weird light in the next hallway until you reach the end. Head through the door and make a left at the "Authorized Personnel only" sign. Go through the door and kill the three dogs at the bottom. Enter the data control operations room and make a left at the authorized personnel only sign into the specimen testing lab. The computer says "message waiting" so hit the button and listen to it. Enter the door and grab the barnacle gun in the glass cage near the door to the left. Enter the door and grab the charger on the table. Go through the specimen cultivation room, kill the three pit drones (one to the left of you, one in front and one below you) and climb down the ladder. Grab the spores at the bottom and use your barnacle gun on the green patches on the ceiling to get up to the other side. Go throught the door and head left down the life near the "Testing Lab BDRC-101" sign. Go through the security door and kill the three headcrabs headcrabs in this room. Just avoid the barnacles and head through the door at the end. In the next room head left and go up the lift. Go through the door and kill two pit drones and the shock trooper. Head up the small staircase and go through the door. Head right and smash the green box to get a charger and head through the door. Avoid the tentacle and drop down. Use your barnacle gun on the green patches directly above the tentacle to get up. Go down into the vent and crawl through until you reach the end. Grab the ammo, health and grenades then flip the unit 1 power switch. Climb up the ladder break the casing on the fan unit 1 and crawl through. "The Pit Worms Nest" Oh boy, the Pit Worm, A.K.A your first boss battle. Go forward and open up the red door. Kill the spitter on the other side and jump through. Flip the switch and go through the waste station 01 door. Climb up the big ladder and at the top and grab the ammo by the dead soldiers. Go left past the Black Mesa Waste Processing Area 3 sign and go through the waste station door. This my friends is the pit worm. You can't harm him with bullets so don't even try. Climb down the ladder and head right into the next room. Kill the two drones in this next hallway and go forward. Kill the two drones by the broken staircase and drop down. Turn around, grab the ammo in the nest, break the vent case and crawl through. Don't worry about the Flush Toxi waste panel, you can't activate it yet. Head left through the Waste Station 02 door and go through this hallway. When your by the Pit Worm, run across until your safely through the next door. Flip the waste access switch and go through the door. Kill the drone by the dead security guard and climb down the ladder. Grab the ammo by the dead soldier and go through the door. In the next room kill the drone, grab the ammo by the dead soldier and jump into the room with the boxes. Climb across the boxes until your on the other side and jump through the door. Avoid the barnacles and jump across the toxic waste until your on the other side. Take the elevator up, walk across the metal grating and kill the two drones. Hit the red button and after the crusher stops take the elevator down. Go back to the room with the boxes and grab the health ammo, and the charger. Break the case in the middle of the room and drop down. Climb up the ladder and break the measuring glass. Go through this hallway and kill the spitter at the end. Head right past the outake signs and hit the emergency override button. The water will rise so quickly get back into the room where you dropped down and let the water take you back up. Head left back to the room with the dead soldier and go all the way back to the Waste Station 01 door (by the pit worm.) Flip the switch again and run back until your back in the room with the Flush Toxic waste panel. This time head right through the door. Go through this hallway and kill the drone by the dead soldier. Grab the ammo and health and climb up the ladder. Kill the two drones at the top and grab the health and ammo. Go through the hallway until you see the steam vent switch by the Pit Worm. Flip the switch and use your barnacle gun to get across. Turn the pressure valve, jump down and head left until your back in the room with the dead drones. Once agin head down the hallway. Jump down at the broken staircase, but this time go forward then left into the room with the flush toxic waste panel. Go up and flush the toxic waste to get rid of this horrible creature. Go right, through the door, climb through the ladder and go through the hallway. Jump down and climb up the ladder to your left. Hit the bridge control button and walk across the bridge. Flip the sewer acess switch and go through the door. "Foxtrot Uniform" Go through the door an kill the spitter on the otherside of the metal grating. Now jump across to where you killed the spitter and go through the door to your right. Kill the spitter and break the green boxes to get health. Now, you see those green organic patches? Well look up at the celing and use your barnacle gun to get through the hole in the wall. Just keep going up until you reach the top and climb up the ladder. Ah, the surface! You will see a truck pull up, be warned though its full of black ops. First things first, get in the back of the red cart and grab the chain gun. Kill the first three black ops nearest you. On the right side there's a turret so go up to the truck where the turret can't hit you and shoot the explosives near it. After its destroyed, grab the rockets and grenades by it and climb up the broken red cart. At the opening on the left side theres two black ops on the ground. After you kill them, drop down and kill the black op in the tower. Before you continue forward break the green boxes near the tower to get some rockets. Continue forward and crawl trough the hole in thw tower to your right. You will see two soldiers so grab all the health and ammo on the shelves and go gorward through the door. Right when you go through the door turn right and kill the black op in the tower. Then turn left and shoot the explosives to kill another black op. Turn right and use a long ranged gun to kill the sniper in the tower in front of you. Go forward and turn right at the explosive boxes. Don't shoot them or else you and the place will go up in flames. Anyway, after you turn right kill the black op in the tower. Turn around and go behind those explosive boxes to the right of the building. Kill the three black ops (one to your left, one to your right and one in front of you.) Make your first left and enter the building by the explosive tanks. Kill the black op inside and go through the opening by the boxes and grab the ammo inside. Head out and go forward near the red and blues crates. There are three black ops so kill them and grab the sniper rifle by the explosive crates to your left. Just go forward through the opening into the builiding. Head forward then turn left at the boxes. Theres a big gunfight so wait until its over and jump into action. There should be only three shock troopers left, so kill them and grab any ammom left by the black ops. Get in the truck to your right and break all the boxes to get some health and ammo. Now head forward from the truck to the other side and go down the ladder to the left. Okay I must warn you now, this is one of the hardest moments in the game. This is the voltigore maze. Go forward, left then left again and keep going forward until you come to a complete stop. Head left then left again and go forward. Make your first right and go directly under the pipe in front of you. Head right under the pipe and head left into the water. Go forward, head right and climb up the ladder at the end. Kill any pit drones that appear abd pull the lever to close the door, which stops them from comming. Head left and do the same thing with the lever in front of you. Turn right at the hole in the wall and just follow the path until you encounter the voltigore. Head forward then left at the end then just make your first right into the hole in the wall. Theres only baby voltigores here so its not that bad. Turn right and head directly forward, past the egg shell, until you reach the end of the hallway and head right. Follow the pipe then head left and climb up the ladder. Let the engineer open the case and head up. Grab the ammo and health on the shelves and head left. Head left outside and kill the five shock troopers and the voltigore (with the assist of your troops.) Turn right at the space between the red and blue carts and shoot the explosive barrel. Go inside the open cart and grab the explosives inside. Head out and go forard and right. Head right and shoot the explosive barrel. Go forward and kill the five shock troopers that come towards you. Turn right at the end and grab the health and explosives. Head forward, left then right by the fire. Kill the three shock troopers at the end and head right and walk directly forward until you go through the broken secure access door. Head right and go through this path until you reach the room with the boxes. Use the first aid kit and armor charger and head out. Ignore that huge monster and head left into the lake. Go directly down the wall and into the opening by the red light. When you reach the other side turn around and use your barnacle gun on the organic patches by the wall. When you get up, push the detenator to kill the monster then kill the three shock troopers that rush towards you. Go to where the monster was and head inside the pipe. Head forward until the casing breaks and let the stream carry you away. "The Package" Make a left at the stream break and when you get out swim to the surface. Continue forward until you meet up with some soldiers and follow them into the battle. First off, kill the black op in the river by the downed helicopter. Sneak around the turret by the helicopter and two black ops should run towards you by the river. Kill them and shoot the explosive barrels by the turret. Now three black ops should come out of the area you met the soliders at so kill them and go to the helicopter. Go straight forward by the helicopter into the land locked stream where the two black ops came from. Just follow this path until you reach the wide open area with the base. Head right into the destroyed bunker and grab the ammo and health by the dead soldier. Three shock troopers should appear outside the bunker, so kill them and head out. Now theres a rocket turret firing at you to the northwest of the water tower. Pull out your sniper rifle and take out the guy firing it. At the north end of the area you should see a "Ordinace Storage Facility" sign. Head right of there and you will see a metal door. Head inside and kill the black op by the stairs. Listen to the radio then head back up the stairs. Break the boxes to get some health and exit. Two black ops should waiting outside near the destroyed bunker. Go straight forward until you see an underground bunker with the cover open. Go inside and follow the linear path until you see the dead soldier by the broken radio. Grab his ammo and jump on the little box to his left. Just jump across the boxes until you reach the pipes. Jump in between the pipes and head forward. Follow the path until you reach the security door. Head up the stairs until you reach the blue sign pointing left and the red sign pointing right. A black op will come out of the right side so kill him and head right. Kill the black op in this room and break all the boxes to get ammo and health. Head back and this time follow the blue sign. Kill the two black ops at the top of the stairs and head up. Go to the very top until you see the metal door. Head through and you will be at the turret. Two shock troopers will appear behind you so kill them and get on the turret. Your gonna want to destroy the metal gate to your far left. Its hard to describe how to do it, so just fiddle with your up/down and left/right controls and fire often until you get a direct hit. After its destroyed two shock troopers and a voltigore will come out. Head down the walls of the base and kill them. Go through the broken gate and into the metal door. Go through this area until you reach the opening in the wall. Theres a voltigore and two shock troopers so kill them. A helicopter should be flying above you so avoid its fire. From the red door head forward into the hole in the wall. Kill the shock trooper and grab the ammo to your left. Go forward and head up the broken stairs. At the top head right at the hole in the wall and drop down. Grab the chargers and ammo in the turned over truck and head forward. Grab the ammo in the flipped over dumpster and head up the ladder. Jump on the heater on the top of the building and jump on the other roof. Go forward and down within the metal fence. Crouch through the slightly open red storage door and go through the metal door. Grab the rocket launcher and flip the power switch. Head back outside and climb up the ladder. Below the giant heater there is an electrical wire. Since you knocked out the electricity walk across it and go to the vents. One of the cases is broken so drop down into it until you reach the parking garage. Kill the two pit drones at the bottom and grab the ammo in the security booth. Head down the ramp and kill the shock trooper. Just head down until you reach the bottom. Kill the first two shock troopers you see and wait for the voltigore to deal with the black ops. Kill the voltigore and any shcok troopers that are still alive. Head to the SUV and break the boxes by it to get some health and ammo. Climb up the SUV into the vent and talk to the security guard hiding there. Head through the vent until you reach the other side. Drop down and kill the two black ops you see. Break all the boxes to get some ammo and head towards the open metal gate with the stop sign on it. Head through and kill the two black ops arming the bomb. Disable it by pressing the use key on it and head back to the security door with the guard standing behind it. After he lets you through break the box by him to get some rockets. Head down this path to the lift and grab the health and ammo on the shelves before entering it. "Worlds Collide" Final chapter, good job on making it this far. After you get off the lift go straight forward and take you second left at the boxes. There should be three black ops firing at you, but more will come. Usually they will come from the north east side so take them all out. When there all dead and you don't hear any footsteps turn left. Go forward then right at the red box and you should see the storage unit 2 sign. Make a right and there should be a black op waiting for you. Before you make a left by the metal crate, be warned that theres a guy waiting on a turret. Use a grenade or any other explosive to take him out. Go inside the bunker where he was and grab the ammo inside. Head left where the boxes are moving to and make a left at the red crate. Jump on the metal boxes to get up and break the small wooden crates to get some ammo. Drop down at the left side at the end and when the crate in front of you moves run to the opening on the left side. Do the same thing to get to the right side. Kill the two black ops on top firing at you and head forward. Break the wooden crates to your left to get ammo, then use the lift to your right. At the top, head to the opening in the boxes in the middle. Just follow the linear path until you see the metal crates. Kill the two black ops in this area and break the boxes to get health and ammo. Jump on all the metal and wooden crates until you reach the top. When your at the top and you have the option of heading left or right, head right. Theres a battle going on beneath you so wait until black ops are dead and kill the remaning aliens. Jump across the two swinging crates and on to the red crate. Walk across the metal railing to your right and jump on the wooden crate at the end. Jump across the other wooden crate and drop down on the red crate below it. Break the boxes to get health, then head left and go up the ramp. After the security guard opens the door charge up on health and armor. Grab all the ammo on the shelves and take the elevator down. Some "force" is pushing you back so just head forward and go down the stairs. At the bottom break the two boxes to get some ammo. Go through the door and climb up the rope next to the ladder. Theres a healing pool at the organic end of the metal grating, so use that when your health gets low. When facing the giant portal get on either the right or left side gun and wait for all the energy orbs to enter the portal... You see the giant creature? Thats the Master Alien, the final boss of the game. Whatever side your on doesn't mater. Shoot either his left or right eye on the side of its head and run across the rail to the other gun and do the same. After you shoot both eyes his stomach will open with a purple orb inside. Shoot the orb with either the laser guns or your own weapons until he fires out a red portal. A shock trooper will come out of this portal so kill it. After you shoot one of its eyes again it will break the bridge connecting the two gun areas. To get to the left side after this just use your barnacle gun on the organice patch at the top. To get to the right side, go down the ladder when at the left side and walk across to rope. Repeat this process 4-5 times using your guns (I'm talking about heavy weapons like the rocket launcher or the chain gun) or 6-10 time using the laser guns until it dies. The End! ==================================== 7. FAQS Q: Wait, theres something wrong with your guide A: If you found a mistake contact me so I can correct it Q: Can I contact you about my other guides? A: sure just use my contact info Q: What happened to Constantanople? A: The turks changed it to Istanbul ==================================== 8. Contact Info. My AIM is InfernalSanchez and my e-mail is DSanche2001@yahoo.com and if you live in the computer I'm virus number 00001000010111100010 ===================================== 9. Thanks - thanks to Gamefaqs.com - Thanks to the readers (all 3 of them) - Valve who made the game - and me, with too much free time