“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!”