"Well, what do you think of it, my dear?" Mrs. Dillon questioned eagerly.
"Beautiful!" the guest praised, stepping back a pace that she might view the painting to better advantage. "How fortunate you are to own such a picture."
"I've always craved to possess a genuine masterpiece," Mrs. Dillon declared enthusiastically. "It gives one prestige."
"And you say this is a Rembrandt, Mrs. Dillon?" the other asked. "It must have cost you a pretty penny."
"It did, but at that I consider the painting a great bargain. The dealer assured me that if I wished to dispose of it at any time he would promise to find an immediate purchaser."
"Undoubtedly, you made a fine deal," Mrs. Dillon's friend acknowledged. "From whom did you buy the picture?"
"I can't tell you that. I pledged myself not to reveal his identity."
"Oh, I see. But you are quite sure you can depend upon the dealer's word?"
"Yes, indeed. I hope you don't think I'd allow myself to be taken in——"
"Oh, no, certainly not. Only I've heard it said that unscrupulous dealers sometimes resort to tricks."
"I pride myself upon having a streak of Yankee shrewdness," Mrs. Dillon said, "and I do know art. When I saw this picture I recognized it instantly as one I had seen at the Gage Galleries. Of course, the dealer didn't claim it was the genuine Rembrandt—quite the contrary."
"Then aren't you afraid——?"
"Not in the least," Mrs. Dillon interrupted. "Naturally, the dealer wouldn't subject himself to arrest by acknowledging that he was selling stolen property."
"The painting is a very fine one," the other woman declared, "but I can't say I should care to own it myself. You'll never be able to display it openly."
"Perhaps not, but I can show it privately to my friends and I'll derive satisfaction just from knowing I own it."
"But if the police should suspect——"
"They won't, unless someone reports me. So far you are the only person who knows that I have the painting."
"Oh, you may trust me, Mrs. Dillon. I'll never give you away."
"If the picture should ever be traced to me I can always claim that I was an innocent purchaser," Mrs. Dillon chuckled. "In fact, I don't know that this is the same picture that was taken from the Gage Galleries. The dealer didn't tell me that it was an original."
"You're very shrewd," the other woman praised.
Mrs. Dillon carefully drew the velvet curtain over the painting and closed the panel. As the two women moved toward the door they passed close to Penny's chair. The girl held her breath, fearing detection.
She had not meant to be an eavesdropper, but the nature of Mrs. Dillon's conversation had made it impossible to reveal her presence in the room without creating a difficult scene. However, should she be discovered now, crouching behind the back of the chair, the situation would prove even more embarrassing.
"We must return to the others before we're missed," Mrs. Dillon said, unlocking the door.
The two women went out, and Penny heard a slight metallic click which at the moment did not strike her as having any significance. As the door closed she quickly arose from her chair.
Penny was dismayed at what she had seen and heard. It was difficult for her to believe that Mrs. Dillon owned the painting which had been stolen from the Gage Galleries. From the conversation she felt quite sure that the society woman had purchased the picture from a dishonest dealer who undoubtedly had received it from the original thief. Yet Mrs. Dillon had knowingly purchased stolen property and so in effect was an accessory to the crime.
"She must be crazy to involve herself in a deal like that," Penny thought. "If the police learn she has the painting they'll confiscate it and arrest her."
Penny realized that she had it within her power to expose Mrs. Dillon. Even though she were a guest in the society woman's home, it was really her duty to reveal her findings to the police.
From her hiding place behind the chair, Penny had not been able to secure a very good view of the painting. She was eager to examine it at close range.
Did she dare open the panel? She decided to take the chance. Jerking at the long silken rope as she had seen Mrs. Dillon do, the girl was gratified to observe the sham picture above the mantel swing slowly back to reveal the hidden panel.
Penny quickly drew aside the velvet curtain which protected the stolen Rembrandt.
The painting was one of the lesser known works of the famous artist, a picture of a child. Penny snapped on the electric light that she might view it to better advantage.
At first glance the painting was very impressive, but as the girl studied it more critically, she was assailed with doubt. The picture did not seem to have the character or strength commonly associated with great works of art. The draftmanship seemed mechanical, the color lacked depth.
"I wonder if it really is a genuine Rembrandt?" Penny thought.
The longer she gazed at it the more convinced she became that the picture was merely a clever imitation. She wished that Amy Coulter were there to offer an opinion. Penny did not trust her own judgment. Her knowledge of art was so slight that she might be mistaken in considering the Rembrandt a fraud.
Closing the panel, Penny sat down for an instant to think. She knew she had made an important discovery, one which easily could cause Mrs. Dillon serious trouble should she report her findings to the police. Upon the other hand, the society woman was an important personage of Belton City with many influential friends, and should she be falsely arrested the trouble would descend like an avalanche upon the head of Penny Nichols.
"I'll have to move cautiously," the girl reflected. "It's no crime to own a copy of a stolen painting. If this picture is a fake, the police would have no case against Mrs. Dillon."
The problem was too deep for Penny. She decided to reveal to no one the discovery she had made until after she had discussed the matter with her father. Quickly, she arose and went to the door.
To her surprise it did not open when she turned the knob. It took an instant for the truth to dawn upon her. The door was locked!
"Mrs. Dillon must have turned the key when she went out," Penny thought, recalling that she had heard a slight metallic click. "Now I am in it!"
She considered calling for help but immediately abandoned the idea. It would be difficult to explain how she had been locked in the library without revealing the true details. And Mrs. Dillon would instantly suspect that she had seen the hidden painting.
The room had two windows looking out upon the front lawn. Directly beneath was a cultivated bed of flowers which Penny decided must be sacrificed if necessary to the occasion. She switched out the electric lights, and raising one of the windows peered in both directions to see that the coast was clear.
Quickly she climbed over the sill, hung by her fingers tips for an instant, then dropped lightly down to the ground, crushing several choice plants underfoot.
Before she could turn she felt her arms pinioned behind her back in a grasp of steel.
"Not so fast, young lady!" said a gruff voice.
Penny whirled around to face the man who had captured her. She began to laugh.
"Dad!"
"Penny! I thought I had caught a young lady burglar. What are you trying to do?"
"Escape from the library."
"So I observe. But have you any objection to using a door? In polite society I believe that's the accepted method of leaving a house."
"The library door was locked," Penny explained hastily. "And I have good reason for wanting to get away without being seen by anyone."
"In that case, always close the window after you," Mr. Nichols chuckled. "Here, I'll boost you up and you can pull it down."
After Penny had lowered the sash, they hurriedly moved away from the window.
"Now tell me all about it," the detective invited. "Did you lose your bag of loot?"
"You know very well I wasn't doing anything I shouldn't," Penny countered, "but you nearly frightened me to death when you nabbed me."
"I just happened to see you climbing out of the window as I came up the path," the detective smiled. "I thought perhaps someone was escaping with the family jewels."
"Speaking of jewelry, there's plenty of it around tonight. The ballroom is fairly ablaze with it."
"Never mind the jewelry," Mr. Nichols said. "What were you doing in the library?"
Leading her father to a secluded stone bench in the garden, Penny related all that she had seen and heard.
"I wish you could see the picture," she ended. "I'm almost certain it's a fake. If I can smuggle you into the library, will you look at it?"
"No, Penny, I will not. You seem to forget that we're guests of Mrs. Dillon."
"Yes, but if she has the stolen Rembrandt in her possession, isn't it our duty to notify the police?"
"Do you know that she has the stolen painting?"
"No, in fact I rather suspect she's been cheated by a dishonest dealer."
"In that event, you'd only stir up a hornet's nest without doing a particle of good. In fact, exposing Mrs. Dillon might give the real thief a warning to lie low."
"How do you mean, Dad?"
"Why, the moment Mrs. Dillon is arrested, the dealer from whom she purchased the picture will disappear. Then there will be no way to trace the real thief."
"You're assuming that the dealer and the thief worked together even though the painting which Mrs. Dillon bought may have been a fake."
"It's quite possible, Penny. Some day when the time is more opportune, I'll explain to you how picture thieves work their racket. For the moment I wish you'd accept my opinion that this case is packed with dynamite. My advice to you is to be very sure of what you're doing before you start any action."
"I guess you're right," Penny agreed. "I'll not do anything rash."
"The case may shake down in a few days," Mr. Nichols went on. "In the meantime, Mrs. Dillon isn't going to dispose of her picture. She'll not find it as easy to sell as she anticipates."
The detective arose from the bench after glancing at his watch.
"We'll have to go inside now," he said, "or the party will be over."
They entered the house and after wandering about for a few minutes encountered Mrs. Dillon. She greeted the detective cordially and the smile she bestowed upon Penny disclosed that she had not even noticed the girl's long absence from the ballroom.
"How do you like her?" Penny whispered to her father as they sought the refreshment table.
The detective shrugged. "She serves very good punch."
Mr. Nichols knew nearly all of the guests, either personally or by reputation. Penny noticed that as he appeared to talk casually with one person after another, actually he was surveying the throng somewhat critically.
"You were right about the jewelry," he said in an undertone to his daughter. "That necklace Mrs. Dillon is wearing must be worth at least a cool ten thousand dollars."
"I should think she'd be afraid of losing it," Penny commented.
"Oh, it's probably insured for all it's worth," Mr. Nichols returned casually.
The orchestra had struck up again and as other couples went out on the floor, Penny tugged at her father's sleeve.
"Come on, Dad. Let's dance."
"You know I hate it, Penny."
"Just one," she pleaded. "I've had no fun at all this evening."
"Oh, all right," he gave in. "But remember, one dance is the limit."
"That depends upon how many times you step on my feet," Penny laughed.
Actually, Christopher Nichols was a far better dancer than he imagined himself to be. His steps were introduced in a mechanical routine which sometimes annoyed Penny, but otherwise he made an excellent partner, gliding smoothly over the floor with the ease and grace of a young man.
"How am I doing?" he mumbled in his daughter's ear as he whirled her deftly about to avoid striking another couple.
"Not bad at all," Penny responded, smiling. "Consider yourself engaged for the next dance."
"Only one I said. I don't want to be laid up with rheumatism tomorrow."
"Rheumatism!" Penny scoffed.
She had spoken the word in an ordinary tone but it sounded as if she had shouted it for the music ended unexpectedly in the middle of a strain, trailing off into discordant tones. The amazed dancers halted, looking toward the orchestra to see what was wrong.
Penny felt the arm which her father held about her waist stiffen. A scream of terror rippled over the room.
Two men with white handkerchiefs pulled over their faces, had entered the ballroom through the double French doors opening into the garden. They trained their revolvers upon the dancers.
"This is a stick-up!" one announced grimly. "Put up your hands and stand against the north wall!"
Penny and her father were forced to line up with the other guests. They stood against the north wall, their hands held above their head. Members of the orchestra and servants were compelled to obey the order. While one of the holdup men covered the crowd with his revolver, the other moved swiftly from person to person collecting jewelry, watches and money.
Penny saw Mrs. Dillon, pale and frightened, trying to drop her pearl necklace into a flower pot, but she was not quick enough. The holdup man jerked the string from her hand.
"Oh, no you don't, lady," he snarled. He admired the pearls an instant before dropping them into a small cloth bag which he carried.
Penny stood next in line. She wore no jewelry save an inexpensive brooch which had belonged to her mother. Tears came into her eyes as the thief jerked it from her dress.
"Oh, please don't take that—" she began.
"Make no resistance," Mr. Nichols ordered curtly.
Penny relapsed into silence. She was a trifle puzzled at her father's attitude for she had always imagined that in such a situation he would be the first to fly into action.
The holdup man paused in front of the detective.
"Your money and valuables," he commanded.
"Help yourself," the detective invited cheerfully.
As the holdup man reached into an inside pocket, Mr. Nichols' fist shot out, catching him squarely under the jaw. The startled thief staggered back and dropped his bag of loot. Before he could recover from the blow, the detective wrenched the revolver from his grasp.
"Look out!" Penny screamed. From the opposite side of the room the other holdup man was taking careful aim at the detective.
Mr. Nichols whirled and fired. The shot buried itself in the wall, but it was close enough to the crook to warn him that the detective was no amateur at handling firearms.
"Scram!" he yelled warningly to his companion.
They fled into the garden with the detective in close pursuit. The two thieves were too hard pressed to give any thought to the lost bag of loot. Several shots were exchanged but the men succeeded in reaching their car which was parked in the driveway. The engine roared as they sped away. Springing into his own automobile, Nichols took up the pursuit but he soon abandoned it as useless, returning to the house.
There he telephoned the police, offering not only the license number of the fleeing automobile but a detailed description of the men.
"The radio cruiser ought to pick them up in a few minutes," he told Penny.
While a curious crowd gathered about he took a knife and extracted the bullet which had been fired into the wall.
"What will you do with that?" someone questioned.
"Keep it for evidence," he explained. "And this revolver as well, although now that I've used it, all fingermarks probably have been obliterated."
The women were clamoring for their lost jewelry, so with Penny's assistance, the detective distributed the articles.
"I feel just like Santa Claus taking presents out of my pack," he declared jokingly. "Here's your brooch, Penny. Did you think you were going to lose it?"
"Yes, I did, Dad. I saw red when that man tore it off my dress."
"So did I."
"You certainly didn't show it. You advised me to make no resistance."
"That was because I didn't want you to be shot."
"Then you turned right around a second later and took a big chance yourself. You might have been killed."
"I knew what I was about," the detective returned quietly.
Mrs. Dillon came up to Mr. Nichols, gripping his hand. Her own was trembling.
"You were marvelous, simply marvelous!" she said tremulously. "Never before in my life have I witnessed such a display of courage."
Others joined in the praise until Mr. Nichols was embarrassed. He hurriedly began to distribute the remainder of the stolen jewelry.
"Your necklace," he said to Mrs. Dillon, presenting it to her.
"Thank you, thank you," the woman murmured gratefully. "How can I ever repay you for saving my pearls?"
"By taking better care of them in the future," he responded grimly.
Mrs. Dillon looked slightly offended. "I have always taken excellent care of my pearls, Mr. Nichols," she replied.
"Perhaps your idea of excellent care does not agree with mine. The necklace is insured?"
"No, it isn't," Mrs. Dillon admitted reluctantly. "My husband spoke of attending to it several times but never did."
"You took a great risk wearing the pearls at a function such as this without even the precaution of having detectives on the premises to watch for gem thieves."
"You were here," Mrs. Dillon smiled. "I shall have my husband send you a check in the morning."
"Then I shall be compelled to return it," the detective replied. "May I ask if you have been in the habit of keeping the necklace in the house, Mrs. Dillon?"
"Why, yes, but I assure you I have an excellent hiding place."
Mr. Nichols could not restrain an amused smile.
"An experienced gem thief could probably find it in ten minutes' time. But that's neither here nor there. The point is, you should not keep the necklace in the house at all unless you do not care if you lose it."
"Of course I care," Mrs. Dillon retorted. "That string cost my husband fifteen thousand dollars."
"Then the necklace is even more valuable than I imagined. I should advise you to take it to the bank vault in the morning. Keep it there until you have it fully protected by insurance."
"I'll do it," Mrs. Dillon promised. "I really think your advice is worth following. I have been careless with the pearls."
In a few minutes the orchestra began to play again and the party went on, although many of the guests were still too nervous and excited to dance. They sat in groups discussing the hold-up. Christopher Nichols became the center of one admiring circle after another. He did not enjoy the attention.
"Let's go home," he suggested to Penny. "I've had enough."
"All right," she agreed instantly. "I left my wraps upstairs. I'll get them."
She crossed the ballroom and entered a hallway. As she paused to permit a couple to pass, she noticed that Hanley Cron and Mrs. Dillon were standing at the foot of the spiral stairway, their backs toward her, engaged in earnest talk. She could not help hearing a snatch of their conversation.
"Mrs. Dillon, why don't you take lunch with me tomorrow at my studio?" the art critic invited.
"I should enjoy it, Mr. Cron," the woman replied. "I might drop in after I take my necklace to the bank vault."
"I see you are determined to follow Christopher Nichols' advice."
"Yes, don't you think I should?"
"I believe he is not considered a very reliable detective," the man replied. "However, in this instance, his advice might be worth following."
"I'm glad you think so, Mr. Cron. I'll take the necklace to the bank in the morning."
"Why not come to my studio before going to the bank?" the art critic proposed. "Then I could serve as an escort. With such a valuable package in your possession you really need a guard."
"It is very kind of you to offer," Mrs. Dillon returned, flattered. "I will meet you at the studio at one o'clock and after luncheon we'll go to the bank together."
Penny had reached the foot of the stairs. The two were so engrossed in their conversation that they were unaware they were blocking the path.
"I beg your pardon," she murmured suggestively.
"Oh, I'm so sorry!" Mrs. Dillon exclaimed, moving hastily aside.
Penny gave no hint either by look or action that she had overheard the conversation, but inwardly she raged at Hanley Cron's cutting reference to her father's ability. She slowly climbed the stairs. At the first landing she glanced back over her shoulder and noticed that the art critic was staring after her. His expression startled her.
"How that man does hate me," she thought. "And all on account of a ruined fender. It's too ridiculous!"
Penny had observed during the evening that Mrs. Dillon and Hanley Cron danced frequently together. Apparently, the society woman was flattered by the man's attention, although Penny was at a loss to understand how anyone could consider him attractive. It seemed to her that the art critic deliberately was trying to ingratiate himself with Mrs. Dillon.
She considered the luncheon invitation which Cron had extended to his hostess. While it might have no significance, it tended to confirm her belief that the man was trying to gain the society woman's favor. She wondered, too, why he appeared so eager to accompany Mrs. Dillon to the bank.
"I don't believe it's because he wants to be generally helpful," she told herself shrewdly. "Hanley Cron simply isn't that sort of person!"
As she stood before the bedroom mirror Penny reflected upon what Cron had said about her father. Not reliable indeed! It was evident that the man deliberately was endeavoring to undermine Mr. Nichols' professional reputation.
Unexpectedly, Penny caught a glimpse of her face in the mirror and laughed because she looked so tense and worried.
"There's no use to take it so seriously," she advised herself. "I've merely learned that Hanley Cron may prove to be a dangerous enemy."
A few minutes later as she was driving home with her father, Penny repeated to him the conversation which she had overheard between Hanley Cron and Mrs. Dillon. The detective smiled at the slighting reference made by the art critic but looked disturbed when he learned of the luncheon engagement.
"Before she gets through, Mrs. Dillon will have informed everyone that she is taking the necklace to the vault tomorrow," he said impatiently. "If she ends up by losing the pearls then perhaps she'll know better next time."
Mr. Nichols stopped at the police station for a few minutes to leave the revolver and the bullet which he had retrieved from the ballroom wall. When he returned to the car Penny questioned him regarding the holdup men.
"Have they been captured?"
"No," he replied in disgust, "they got away."
It was long after midnight when they reached home. Penny would have liked to remain up awhile to discuss the exciting events of the evening but Mr. Nichols was too sleepy to be in a talkative mood. He hurried his daughter off to bed.
"I think I'll visit Amy Coulter sometime to-day," Penny remarked the next morning at breakfast. "What I saw last night convinced me that she could have no part in the theft of the painting."
"The picture in Mrs. Dillon's possession doesn't prove anything," Mr. Nichols replied as he pushed aside his coffee cup. "The painting may be a fake. Or if it's genuine this girl may have been one of a gang who negotiated the deal with Mrs. Dillon."
"If you met Amy you'd understand that she isn't the criminal type, Dad."
"And just what is the criminal type? Give me a definition."
Penny threw down her napkin impatiently. "Oh, there's no use arguing with you! You always win!"
"I'm not suggesting that your friend Amy is a crook," the detective smiled. "I'm merely trying to teach you to think and not to arrive at conclusions through impulse or emotion."
After the morning's work was done, Penny telephoned Susan Altman to tell her about the Dillon party. Susan was not at home so she walked to Amy Coulter's rooming house where she was admitted by the landlady.
"I'm so glad you came," Amy cried joyfully as she admitted the girl. "I took your advice and shut myself up here in my castle, but it's been dreadfully lonesome."
The young sculptress had been working on a small statue. After Penny had admired it, she covered the figure with a cloth and set it away.
"I'm worried about my Black Imp," she confessed, offering Penny a chair. "This morning a notice appeared in the paper that all contestants for the Huddleson prize should call within twenty-four hours at the Gage Galleries for their entries. I'm afraid to go for fear I'll be arrested."
"It wouldn't be safe," Penny agreed, "but if we're patient for a few days longer I believe the mystery may begin to clear up. In fact, I have an important clue already."
She then told Amy how she had discovered the Rembrandt in Mrs. Dillon's library. The girl was overjoyed to learn the news for she felt that the recovery of the painting would exonerate her. However, her face clouded as Penny mentioned that the picture might be a fake.
"If I were certain the picture was stolen from the museum, I'd go directly to the police," Penny declared, "but until I am sure I must move cautiously."
"I wish I could see the painting. I feel confident I could tell if it's a fake."
"I wish you could examine it," Penny said, frowning thoughtfully. "Unfortunately, I don't see how it can be arranged—unless——"
"What?" Amy demanded quickly.
"Mrs. Dillon would never permit us to see the painting if she could prevent it. We'd have to get into the house without her knowing it."
"How could we ever do that?"
"I have an idea, but there would be a certain amount of risk to it. Are you willing to take a chance?"
"If it isn't too great a one. I couldn't get into a much worse situation than I am now. The police probably will arrest me upon sight anyway."
"This is the plan," Penny explained. "I happen to know that Mrs. Dillon will be away from the house at one o'clock today for she's lunching with Hanley Cron. While she's gone we'll look at the picture."
"But the servants will be there," Amy protested.
"I think I can arrange it so they won't be suspicious. Do you want to try it?"
Amy hesitated only an instant before nodding her head. "I've nothing to lose and a great deal to gain," she said.
Penny glanced at the little ivory clock on the dresser. It was nearly noon. By the time the girls reached Mrs. Dillon's home the woman should be away.
"It will be wise to go in a taxi, I think," she remarked. "There should be less danger of anyone recognizing you that way."
While Amy changed her clothes, Penny went downstairs to call a cab. It came twenty minutes later and the two drove directly to Mrs. Dillon's residence.
"The coast should be clear," Penny remarked as they alighted at the door. "It's a quarter to one but Mrs. Dillon surely is on her way to meet Cron by this time."
Penny boldly rang the doorbell. Presently a maid answered the summons. Smiling graciously, the girls stepped inside without waiting for an invitation to do so.
"Tell Mrs. Dillon, please, that we have come to see the picture," Penny directed confidently.
"Mrs. Dillon isn't in, Miss."
"Not in?" Penny exclaimed, and turned to Amy in pretended chagrin. "Do you suppose she forgot our appointment?"
"I am afraid so," Amy murmured.
"Mrs. Dillon went away in a great hurry," the maid said apologetically. "She didn't mention that she was expecting guests."
"She failed to say that she invited us here to view the painting?"
"It was an oversight, of course. Mrs. Dillon will be sorry I know to have missed you. Your names—"
"It will be some time before we can come back I fear," Penny interrupted quickly. "And we did so want to see the picture. I don't suppose you could show it to us?"
"I am afraid not. I don't even know what picture she meant."
"Oh, the one hanging in the library," Penny informed. "It would only take us a minute to look at it."
"Why, I guess I could show you that picture."
Forgetting that she had neglected to learn the names of the callers, the maid led them to the library. The girls pretended to study the ugly painting which hung over the mantel.
"Is this Mrs. Dillon's last purchase?" Penny inquired.
"It's the only picture she's bought recently."
The girls shrewdly concluded that the maid was unaware of the hidden panel and were at a loss to know how they could manage to view the Rembrandt.
"I could study a beautiful painting for hours and hours," Amy remarked, sinking down into a chair opposite the mantel.
"So could I," Penny agreed, gazing with a rapt expression at the hideous picture. As an apparent afterthought she turned to the maid who stood waiting. "If you don't mind, we'll just sit here for a few minutes and admire it."
"Certainly, Miss. If you'll excuse me I'll go on with my dusting."
The instant the maid had gone from the library, Penny pulled on the silken rope and the hidden panel was revealed. She jerked aside the velvet curtain to disclose the Rembrandt.
"You'll have to make a quick examination," she warned. "That maid may come back any minute."
Amy studied the painting critically. When she did not speak, Penny impatiently asked for her opinion.
"I believe it's merely a copy of the original, although a rather clever copy. Rembrandt was very skillful in his method of handling light and shade—in this picture it is all lost."
"Then I was right!" Penny cried triumphantly.
"My opinion may not be right, Penny. If I could see the painting in a better light—"
With an anxious glance toward the library door, Penny hastened to the window and pulled aside the heavy draperies. A beam of sunlight fell across the picture.
"Yes, I'm sure it's a fake," Amy decided firmly. "If Mrs. Dillon bought this for the original Rembrandt she was cheated."
"Well, she deserved to be. She shouldn't have tried to buy stolen property."
"Let me look on the underside of the canvas," Amy suggested. "Sometimes that will give a clue as to the age of a painting."
They pulled the picture out from the wall and peered behind it. Directly in the center of the canvas was a strange, complicated symbol and beneath it the initials, "G. D." Both had been inscribed in India ink.
"What's that for?" Penny questioned.
"I wonder myself," Amy replied.
"Then it isn't customary to put symbols or initials on the back of a painting?"
"Decidedly not."
The girls studied the marking for a minute. They could make nothing of it.
"I can't explain the symbol," Amy said, "but I'm convinced this painting is a fraud."
Penny had expected such a verdict as it confirmed her own observations, but for her friend's sake she was sorry that the painting had not turned out to be the original Rembrandt. Had they actually located the stolen picture it would be a simple matter to lay their evidence before the police and demand that Mrs. Dillon be forced to reveal the dealer from whom she purchased the property.
"Everything is in a queer muddle now," Penny commented thoughtfully. "Mrs. Dillon really isn't guilty of any crime at all, for she didn't buy a stolen picture. We can't very well cause her arrest."
"Mrs. Dillon should complain to the police that she was cheated."
"She doesn't know it yet," Penny chuckled. "When she finds out about it, I imagine she'll never report the dealer. Her own part in the affair would be too humiliating. Even if she didn't buy stolen property, that was her intention."
"I suppose the real crooks counted upon just such a reaction," Amy said. "When they sold her that fake painting they knew they were safe."
"And in the meantime the genuine Rembrandt is still missing," Penny replied musingly. "I have a suspicion this dishonest dealer, who sold Mrs. Dillon the fake picture, might be able to throw a little light upon the subject."
"But how will we ever trace him unless we notify the police?"
"I am afraid that would be a sure way of losing his trail completely," Penny replied. "Mrs. Dillon's arrest would be the signal for the dishonest dealer to get out of town."
"That's probably true."
"We must work this thing out cautiously," Penny declared. "Perhaps if we went to Mrs. Dillon and talked with her—"
She broke off as they heard approaching footsteps in the hall.
"The maid!" Amy whispered.
"Quick!" Penny exclaimed in an undertone. "Help me get this picture back into place before she comes!"