"Exactly! How could a man in this room kill a man in the next room? That is the problem I have been working at for an hour. And I believe I have solved it. Listen. Between these rooms is a solid wooden partition with no door in it—no passageway of any kind. Yet the man in there is dead, we're sure of that. The pistol was here, the bullet went there—somehow. How did it go there? Think."
The detective paused and looked fixedly at the wall near the heavy sideboard. Tignol, half fascinated, stared at the same spot, and then, as a new idea took form in his brain, he blurted out: "You mean it went through the wall?"
"Is there any other way?"
The old man laid a perplexed forefinger along his illuminated nose. "But there is no hole—through the wall," he muttered.
"There is either a hole or a miracle. And between the two, I conclude that there is a hole which we haven't found yet."
"It might be back of that sideboard," ventured the other doubtfully.
But M. Paul disagreed. "No man as clever as this fellow would have moved a heavy piece covered with plates and glasses. Besides, if the sideboard had been moved, there would be marks on the floor and there are none. Now you understand why I'm interested in that Japanese print."
Tignol sprang to his feet, then checked himself with a half-ashamed smile.
"You're mocking me, you've looked behind the picture."
Coquenil shook his head solemnly. "On my honor, I have not been near the picture, I know nothing about the picture, but unless there is some flaw in my reasoning——"