“When he’d smashed the glass of the case, he took out the whole six medallions, and not merely three of them as he told you he’d done.”
“And then?”
“He pocketed the replicas and stuck the real things under the case with plasticine. Then he continued the false trail by bolting out of the house. He was the man in white. When he got clear of the people who were chasing him, he came back to the house again, ready to play his part as an innocent practical joker. And he had his tale ready, of how some one was beside him at the case, wearing a Pierrot costume. That stamped the notion of an outside gang on everybody’s mind. Both sets of medallions had gone. He—the innocent practical joker—could have produced the replicas from his pocket and sworn they were all that the gang had left in the case by the time he got to it.”
“And . . . ?”
“And then, a few days later, he’d have managed to get into the museum on some excuse—he’s a friend of the family—and he’d have had no difficulty in taking the real medallions from under the case where he’d left them. He’d have to take the chance that they’d been overlooked. The false trail would help in that. He’d hardly expect a close search of the museum after the man in white had got clear away. And by running the business on these lines, he’d avoid any chance of being caught with the stuff actually in his pocket at any time.”
“But in that case, why did he hand over the real things to me like a lamb as soon as I challenged him?”
The Inspector was ready for this.
“Because as soon as he came into the museum last night, he found that you apparently knew everything—or a good deal more than he’d counted on. Anyhow, he didn’t know how much you knew; and he felt he’d got into a tight corner. He just let the whole thing slide and made up his mind to get out before things got too hot. So he pretended that so far as he was concerned, the practical joke was the thing; and he gave up the real medallions and kept the replicas in his pocket.”
“Why? He might as well have given up the lot.”
“No,” the Inspector contradicted. “He’d got to keep the false trail going, for otherwise there would have been awkward questions as to why he diverged from the prearranged programme. I mean the shooting out of the light, the lies about the man in white, and so forth. So he stuck to the replicas and made out that there was an outsider mixed up in the affair. But thanks to the practical joke, the outsider had missed the real stuff; and Polegate was really the saviour of the Leonardo set.”