"By Jove, I have it!" cried Jack. "Here is the clew! Look, Alphonse! The scoundrel, whoever he was, took an impression in wax on his first visit. He had a key made from it, came back later at night, and stole the picture. It was a cunning piece of work."
"Monsieur is right," said Alphonse. "A thief has robbed him. You suspect nobody?"
"Not a soul," replied Jack.
Though the shreds of wax showed how the studio had been entered, he was no nearer the solution of the mystery than before. He excepted the few trustworthy friends—only three or four—who knew that he had the duplicate Rembrandt.
"And even in Paris there were not many who knew that I painted the thing," he thought. "I painted it at the Hotel Netherlands, and when Von Whele went home and left it on my hands, I locked the canvas up in an old chest. No, I can't suspect any of my friends, past or present. But then who—By Jove! I have overlooked one point! The man who stole the picture knew just where it was kept, and he went straight to it. Otherwise he would have rummaged the studio, and disarranged things badly before he found what he wanted."
A light flashed on Jack—a light of inspiration, of certainty and conviction. He remembered the visit of M. Felix Marchand, that he had commented on the painting, and had seen it restored to its place in the portfolio. Beyond doubt the mysterious Frenchman was the thief. Armed with his craftily-won knowledge, provided with a duplicate key to the studio, he had easily and safely accomplished his purpose. At what hour, and on what night, it was impossible to say. Probably a day or two after his first visit in the guise of a buyer.
"Monsieur must not take his loss too much to heart," said Alphonse, with well-meant sympathy. "If he informs the police—"
"I prefer to have nothing to do with the police, thank you. You may go, Alphonse. I shall dine in town, as usual."
When Alphonse had departed, Jack threw a sheet over the canvas on his easel, put on a smoking jacket, lighted his pipe, and stretched himself in an easy chair, to think about the startling discovery he had made.
The mystery presented many difficult points for his consideration. The rogue's sole aim was to get that particular painting, and he had taken nothing else, though he might have walked off with his pockets filled with valuable articles. He probably expected that the robbery would not be discovered for a long time.