THE MACHINE ROOM ================ Human machinery ends here. A rusty steel cabinet stands beside black resonant structures like the ones beneath Lake Koshkonong. The cabinet contains a knife switch, a master reset, a relay tester and a circular socket shaped exactly like the metal key. The resonators are aimed down the corridor, not at the surface. Every few seconds they flex without making a sound. Above the socket, someone has stenciled: RETURN LINE / AUTHORIZED MAINTENANCE ONLY