Hatch didn't have any very definite idea as to just what he could do, so he let him go on."As I understand it, Mr de Lesseps,"he interrupted at last,"no one else was in the room, except you and Mr Kale, all the time you were there?"

"No one else."

"And I think Mr Kale said that you were making a copy of some famous water color, weren't you?"

"Yes, a Thames scene, by Whistler,"was the reply."That is it, hanging over the mantel."

Hatch glanced at the picture admiringly. It was an exquisite copy, and showed the deft touch of a man who was himself an artist of great ability.

De Lesseps read the admiration in his face."It is not bad,"he said modestly."I studied with Carolus Duran."

With all else that was known, and this little additional information, which seemed of no particular value to the reporter, the entire matter was laid before The Thinking Machine. That distinguished man listened from beginning to end without comment.

"Who had access to the room?"he asked finally.

"That is what the police are working on now,"was the reply."There are a couple of dozen servants in the house, and I suppose, in spite of Kale's rigid orders, there was a certain laxity in their enforcement."

"Of course that makes it more difficult,"said The Thinking Machine in the perpetually irritated voice which was so distinctly a part of himself."Perhaps it would be best for us to go to Mr Kale's home and personally investigate."

Kale received them with the reserve which all rich men show in the presence of representatives of the press. He stared frankly and somewhat curiously at the diminutive figure of the scientist, who explained the object of their visit.

"I guess you fellows can't do anything with this,"the millionaire assured them."I've got some regular detectives on it."

"Is Mr Mallory here now?"asked"The Thinking Machine"curtly.

"Yes, he is up stairs in the servants'quarters."

"May we see the room from which the picture was taken?"inquired the scientist, with a suave intonation which Hatch knew well.

Kale granted the permission with a wave of the hand, and ushered them into the ball room, where the pictures had been stored. From the relative center of this room The Thinking Machine surveyed it all.The windows were high.Half a dozen doors leading out into the hallways, to the conservatory, and quiet nooks of the mansion offered innumerable possibilities of access.After this one long comprehensive squint, The Thinking Machine went over and picked up the frame from which the Rubens had been cut.For a long time he examined it.Kale's impatience was painfully evident.Finally the scientist turned to him.

"How well do you know Mr de Lesseps?"he asked.

"I've known him for only a month or so. Why?"

"Did he bring you letters of introduction, or did you meet him merely casually?"

Kale regarded him with evident displeasure."My own personal affairs have nothing whatever to do with this matter,"he said pointedly."Mr de Lesseps is a gentleman of integrity, and certainly he is the last whom I would suspect of any connection with the disappearance of the picture."

"That is usually the case,"remarked The Thinking Machine tartly. He turned to Hatch."Just how good a copy was that he made of the Whistler picture?"he asked.

"I have never seen the original,"Hatch replied,"but the workmanship was superb. Perhaps Mr Kale wouldn't object to us seeing-"

"Oh, of course not,"said Kale resignedly."Come in, it's in the gallery."

Hatch submitted the picture to a careful scrutiny."I should say that the copy is well nigh perfect,"was his verdict."Of course, in its absence, I couldn't say exactly;but it is certainly a superb work."

The curtains of a wide door almost in front of them were thrown aside suddenly, and Detective Mallory entered. He carried something in his hand, but at the sight of them concealed it behind him.Unrepressed triumph was in his face.

"Ah, professor, we meet often;don't we?"he said.

"This reporter here and his friend seem to be trying to drag de Lesseps into this affair somehow,"Kale complained to the detective."I don't want anything like that to happen. He is liable to go out and print anything.They always do."

The Thinking Machine glared at him unwaveringly, straight in the eye for an instant, then extended his hand toward Mallory."Where did you find it?"he asked.

"Sorry to disappoint you, professor,"said the detective sarcastically,"but this is the time when you were a little late,"and he produced the object which he held behind him."Here is your picture, Mr Kale."

Kale gasped a little in relief and astonishment, and held up the canvas with both hands to examine it."Fine!"he told the detective."I'll see that you don't lose anything by this. Why, that thing cost me fifty thousand dollars!"Kale didn't seem able to get over that.

The Thinking Machine leaned forward to squint at the upper right hand corner of the canvas."Where did you find it?"he asked again.

"Rolled up tight, and concealed in the bottom of a trunk in the room of one of the servants,"explained Mallory."The servant's name is Jennings. He is now under arrest."

"Jennings!"exclaimed Kale."Why, he has been with me for years."

"Did he confess?"asked the scientist imperturbably.

"Of course not,"said Mallory."He says some of the other servants must have hidden it there."

The Thinking Machine nodded at Hatch."I think perhaps that is all,"he remarked."I congratulate you, Mr Mallory, upon bringing the matter to such a quick and satisfactory conclusion."

Ten minutes later they left the house and caught a car for the scientist's home. Hatch was a little chagrined at the unexpected termination of the affair, and was thoughtfully silent for a time.

"Mallory does show an occasional gleam of human intelligence, doesn't he?"he said at last quizzically.

"Not that I ever noticed,"remarked The Thinking Machine crustily.

"But he found the picture,"Hatch insisted.

"Of course he found it. It was put there for him to find."

"Put there for him to find!"repeated the reporter."Didn't Jennings steal it?"

"If he did, he's a fool."

"Well, if he didn't steal it, who put it there?"

"De Lesseps."

"De Lesseps!"echoed Hatch."Why the deuce did he steal a fifty thousand-dollar picture and put it in a servant's trunk to be found?"

The Thinking Machine twisted around in his seat and squinted at him coldly for a moment."At times, Mr Hatch, I am absolutely amazed at your stupidity,"he said frankly."I can understand it in a man like Mallory, but I have always given you credit for being an astute, quick-witted man."

Hatch smiled at the reproach. It was not the first time he had heard of it.But nothing bearing on the problem in hand was said until they reached The Thinking Machine's apartments.

"The only real question in my mind, Mr Hatch,"said the scientist then,"is whether or not I should take the trouble to restore Mr Kale's picture at all. He is perfectly satisfied, and will probably never know the difference.So-"

Suddenly Hatch saw something."Great Scott!"he exclaimed."Do you mean that the picture that Mallory found was-"

"A copy of the original,"supplemented the scientist."Personally I know nothing whatever about art;therefore, I could not say from observation that it is a copy, but I know it from the logic of the thing. When the original was cut from the frame, the knife swerved a little at the upper right hand corner.The canvas remaining in the frame told me that.The picture that Mr Mallory found did not correspond in this detail with the canvas in the frame.The conclusion is obvious."

"And de Lesseps has the original?"

"De Lesseps has the original. How did he get it?In any one of a dozen ways.He might have rolled it up and stuck it under his coat.He might have had a confederate.But I don't think that any ordinary method of theft would have appealed to him.I am giving him credit for being clever, as I must when we review the whole case.

"For instance, he asked for permission to copy the Whistler, which you saw was the same size as the Rubens. It was granted.He copied it practically under guard, always with the chance that Mr Kale himself would drop in.It took him three days to copy it, so he says.He was alone in the room all that time.He knew that Mr Kale had not the faintest idea of art.Taking advantage of that, what would have been simpler than to have copied the Rubens in oil?He could have removed it from the frame immediately after he canvased it over, and kept it in a position near him where it could be quickly concealed if he was interrupted.Remember, the picture is worth fifty thousand dollars;therefore, was worth the trouble.

"De Lesseps is an artist-we know that-and dealing with a man who knew nothing whatever of art, he had no fears. We may suppose his idea all along was to use the copy of the Rubens as a sort of decoy after he got away with the original.You saw that Mallory didn't know the difference, and it was safe for him to suppose that Mr Kale wouldn't.His only danger until he could get away gracefully was of some critic or connoisseur, perhaps, seeing the copy.His boldness we see readily in the fact that he permitted himself to discover the theft;that he discovered it after he had volunteered to assist Mr Kale in the general work of rehanging the pictures in the gallery.Just how he put the picture in Jenning's trunk I don't happen to know.We can imagine many ways."He lay back in his chair for a minute without speaking, eyes steadily turned upward, fingers placed precisely tip to tip.

"The only thing remaining is to go get the picture. It is in de Lesseps'room now-you told me that-and so we know it is safe.I dare say he knows that if he tried to run away it would inevitably put him under suspicion."

"But how did he take the picture from the Kale's home?"asked Hatch.

"He took it with him probably under his arm the day he left the house with Mr Kale,"was the astonishing reply.

Hatch was staring at him in amazement. After a moment the scientist arose and passed into the adjoining room, and the telephone bell there jingled.When he joined Hatch again he picked up his hat and they went out together.

De Lesseps was in when their cards went up, and received them. They conversed of the case generally for ten minutes, while the scientist's eyes were turned inquiringly here and there about the room.At last there came a knock on the door.

"It is Detective Mallory, Mr Hatch,"remarked The Thinking Machine."Open the door for him."

De Lesseps seemed startled for just one instant, then quickly recovered. Mallory's eyes were full of questions when he entered.

"I should like, Mr Mallory,"began The Thinking Machine quietly,"to call your attention to this copy of Mr Kale's picture by Whistler-over the mantel here. Isn't it excellent?You have seen the original?"

Mallory grunted. De Lesseps'face, instead of expressing appreciation of the compliment, blanched suddenly, and his hands closed tightly.Again he recovered himself and smiled.

"The beauty of this picture lies not only in its faithfulness to the original,"the scientist went on,"but also in the fact that it was painted under extraordinary circumstances. For instance, I don't know if you know, Mr Mallory, that it is possible so to combine glue and putty and a few other commonplace things into a paste which would effectually blot out an oil painting, and offer at the same time an excellent surface for water color work."

"This water color-this copy of Whistler,"continued the scientist evenly-"is painted on such a paste as I have described. That paste in turn covers the original Rubens picture.It can be removed with water without damage to the picture, which is in oil, so that instead of a copy of the Whistler painting, we have an original by Rubens, worth fifty thousand dollars.That is true;isn't it, Mr de Lesseps?"

There was no reply to the question-none was needed. It was an hour later, after de Lesseps was safely in his cell, that Hatch called up The Thinking Machine on the telephone and asked one question.

"How did you know that the water color was painted over the Rubens?"

"Because it was the only absolutely safe way in which the Rubens could be hopelessly lost to those who were looking for it, and at the same time perfectly preserved,"was the answer of The Thinking Machine,"I told you de Lesseps was a clever man, and a little logic did the rest. Two and two always make four, Mr Hatch, not sometimes, but all the time."