“What else do you wish to discover? If there’s anything I can tell you I’ll do so like a shot—although I don’t for a moment expect that there is.”

“Well, we can but try, sir. First of all, merely as a matter of routine, can you give me an account of your own movements today? You understand, I expect, that this is the sort of question that we have to put to every one who is at all likely to be connected with the case—and, after all, some evil-minded people might be inclined to suggest, if you had no alibi, that you had a motive for getting rid of the professor.” Cunningham gave himself a mental pat on the back. He thought that he had managed that in quite diplomatic fashion.

Baker chuckled. “And you yourself would be the first of those evil-minded people, I think, Mr. Cunningham,” he said. “Right. My movements today. Nine-thirty to twelve-thirty, teaching a group of foolish youngsters the rudiments of chemistry—rudiments which they have no doubt forgotten again long before this moment. Twelve-thirty to two, lunching in the company of said boys. Two-thirty to four-thirty, umpiring a cricket match on the school playing-field. Four-thirty, having tea until five-thirty. May seem a long time, but we lingered over cigarettes afterwards. Five-thirty to seven, correcting rottenly written exercise-books. Seven to the moment of your arrival, having dinner and then playing billiards with one of my companions in iniquity, the mathematics master. How’s that, Sergeant?”

“A hundred not out, I should think, sir,” said Cunningham, not showing by a single movement of a muscle that this neat recital of times had impressed him not a whit. He was remembering Shelley’s remark that really this matter of alibis was of no vital importance, it being likely that the poisoned sweet had been placed in the packet at some earlier date, the murderer being sure that the Professor would eat it sooner or later.

“Good. And the next question, please.” Cunningham did not altogether like the flippant way in which this young man was treating the murder of his prospective father-in-law, but he realised that he must not allow a dislike of the young man’s manner to make him in any way suspicious of Baker. Outward appearance, Shelley had often said, was the one thing which the good detective had perforce to school himself to distrust.

“Another routine one, I think, sir,” he said briskly. “Can you suggest anyone who would wish to kill the professor? Had he, in other words, any enemy or enemies who would wish him out of the way?”

Baker thought. “The law of libel or slander or whatever the legal lingo is may be disregarded on this privileged occasion, I take it?” he said.

“Yes,” said Cunningham with a grin. “If you have any suspicions, though they’re only vague, I should advise you to bring them out into the daylight.”