at his throat. He is still gripping the wallet when the life has gone out of him. Had it fallen on the floor, you would have been baffled, for you knew the money was not in the portmanteau which you had already rifled. Look! His knees are drawn up in a death-agony which is grotesquely like that of a sitting man. Here is an alibi. Mercier propped against the window, sitting there as though he were peering out, with his back to the door—you saw the possibility. Nobody could see that he was dead. He would tumble down, of course, after the train started and the movement dislodged him, but if it could be proved that he were alive when the train started, your alibi could be strengthened all along—it was almost perfect. Your error lay in saying that you had taken his ticket, for you wished to keep him alive as long as possible, and you did not want to discover the body—there might be embarrassing questions.”
Bencolin sat down on the edge of the desk and pulled up his trouser-leg. He regarded Saulomon thoughtfully.
“I also made a mistake, M. Saulomon. I should not have gone into the train at all. But, looking through the window outside and seeing Mercier on the floor, I was not unnaturally startled; I came in to see what had happened, and found the door bolted. Then I began to realize what had happened. I wanted to see who was on the train, and when I foolishly exhibited myself at the corridor-window I had to get Sir John and M. Saulomon to swear that they had seen nobody. Why? Well, was it not good tactics? If I revealed myself to the murderer as the prefect of police, got him in the league with me, and threw myself on his mercy for silence, was it not rather good evidence to him that I suspected nothing? Otherwise he would hardly have been so secure in his position, and he would not have deposited in a bank that marked money which
