“I don’t see how that can possibly enter into the matter, except in its bearing on this mysterious car.”

Though Winter was taking the lead, Theydon was aware that Furneaux, who had given him scant attention hitherto, was now looking at him fixedly.  He imagined that the queer little man was all agog to learn something about the automobile which had thrust itself so abruptly into the affair.

“Exactly,” he agreed.  “I visited Mr. Forbes tonight for the first time.  We are mutually interested in aviation.  That is why I went to Brooklands today, and the invitation to dinner was the outcome of a letter of introduction given me by Professor Scarth.”

Then, thinking he had said enough on that point, he described the gray car and its stolid-faced chauffeur to the best of his ability.  He told of the brief chat with the taxi driver and its result.

“Good!” nodded Winter.  “I’m glad you did that.  It may help.  I am doubtful of any information turning up, but you never can tell.  The number plate, at any rate, is certainly misleading.  Now, about last night?  Try and be as accurate as possible with regard to time.  Can you give us the exact hour when you returned home?”

“I happened to note by the clock on the mantelpiece that I came in at 11:35.”

Winter compared the clock’s time with his watch.

“You had been to a theater?” he said.

“Yes—­ Daly’s.”

“It was raining heavily.  Did you take a cab?”

“Yes.”

“Were you delayed?  The piece ended at 11:05.”

“My cab met with a slight accident.”

“What sort of accident?”

Theydon explained.

“In all likelihood you can discover the driver,” he smiled, “and he will establish my alibi.”

His tone seemed to annoy Furneaux, who broke in: 

“Don’t you write novels?”

“Yes.”

“Sensational?”

“Occasionally.”

“Then you ought to be tickled to death, as the Americans say, at being mixed up in a first-rate murder.  This is no ordinary crime.  Several people will be older and wiser before the culprit is found and hanged.”

“What Mr. Furneaux has in mind,” purred Winter cheerfully, “is the curious habit of some witnesses when questioned by the police.  They arm themselves against attack, as it were.  You see, Mr. Theydon, we suspect nobody.  We try to ascertain facts, and hope to deduce a theory from them.  Over and over again we are mistaken.  We are no more astute than other men.  Our sole advantage is a wide experience of criminal methods.  The detective of romance—­ if you’ll forgive the allusion—­ simply doesn’t exist in real life.”

“I accept the rebuke,” said Theydon.  “I suppose the gray car was still rankling in my mind.  From this moment I start afresh.  At any rate, the man who brought me from the theater might check my recollection of the time.”

Winter nodded.  He was evidently pleased that Theydon was inclined to share his view of the difficulties Scotland Yard encountered in its fight against malefactors.