"Ah!" said Rouletabille, "there are footmarks visible on the path—the ground was very moist. I will look into that presently."
"Nonsense!" interrupted Daddy Jacques; "the murderer did not go that way."
"Which way did he go, then?"
"How do I know?"
Rouletabille looked at everything, smelled everything. He went down on his knees and rapidly examined every one of the paving tiles. Daddy Jacques went on:—
"Ah!—you can't find anything, monsieur. Nothing has been found. And now it is all dirty; too many persons have tramped over it. They wouldn't let me wash it, but on the day of the crime I had washed the floor thoroughly, and if the murderer had crossed it with his hobnailed boots, I should not have failed to see where he had been; he has left marks enough in Mademoiselle's chamber."
Rouletabille rose.
"When was the last time you washed these tiles?" he asked, and he fixed on Daddy Jacques a most searching look.
"Why—as I told you—on the day of the crime, towards half-past five—while Mademoiselle and her father were taking a little walk before dinner, here in this room: they had dined in the laboratory. The next day, the examining magistrate came and saw all the marks there were on the floor as plainly as if they had been made with ink on white paper. Well, neither in the laboratory nor in the vestibule, which were both as clean as a
