“That’s what I say, sir.”

“Then it seems almost certain that Mr. Ackroyd himself must have admitted this stranger. But I don’t quite see⁠—”

The inspector went into a kind of daydream for some minutes.

“One thing’s clear,” he said at length, rousing himself from his absorption, “ Mr. Ackroyd was alive and well at nine-thirty. That is the last moment at which he is known to have been alive.”

Parker gave vent to an apologetic cough which brought the inspector’s eyes on him at once.

“Well?” he said sharply.

“If you’ll excuse me, sir. Miss Flora saw him after that.”