“Maybe not,” said the inspector tonelessly.

“What have you got against him?” I asked.

“Went out just on nine o’clock last night. Was seen in the neighbourhood of Fernly Park somewhere about nine-thirty. Not been seen since. Believed to be in serious money difficulties. I’ve got a pair of his shoes here⁠—shoes with rubber studs in them. He had two pairs, almost exactly alike. I’m going up now to compare them with those footmarks. The constable is up there seeing that no one tampers with them.”

“We’ll go at once,” said Colonel Melrose. “You and M. Poirot will accompany us, will you not?”

We assented, and all drove up in the colonel’s car. The inspector was anxious to get at once to the footmarks, and asked to be put down at the lodge. About halfway up the drive, on the right, a path branched off which led round to the terrace and the window of Ackroyd’s study.