"I was dining with Mr. James Creighton Forbes, of No. 11, Fortescue Square," he said. "Probably you are acquainted with his name, so you will realize that if my evidence proves of the slightest value I would not like any reference to be made to the fact that I was his guest tonight."
"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.
"Did you see or meet any one in particular while your car approached these mansions, or when you ascended the stairs?"
"No," said Theydon.
He perceived intuitively that if the detectives found the driver of the taxi which brought him from the theater it was possible the man might have noticed Forbes, who had certainly been scrutinized a few minutes later by a policeman, so he hastened to add:
"You said 'any one in particular.' I did see a tall, well-dressed gentleman at the corner of the street, but there is nothing remarkable in that."
"Which way was he heading?"
"In this direction."
"Then it is conceivable that he might be the man who called on Mrs. Lester?"
"Yes."
"Aren't you pretty sure he was the man?"
Theydon permitted himself to look astonished.
"I?" he said. "How can I be sure? If you mean that, judging from the interval of time between my seeing him at the corner and the sound of footsteps on the stairs, followed by the opening of the door at No. 17, it could be he, I accept that."
Winter nodded again. Apparently he was content with Theydon's correction.
"As the weather was bad, you probably hurried in when your cab stopped?" he said.
"That is equivalent to saying you credit me with sense enough to get in out of the wet," smiled Theydon.
"Just so. And you wore an overcoat, which you removed on entering your hall?"
"Yes," and Theydon's tone showed a certain bewilderment at these trivialities.
"Then if you paid no special heed to the movements of the tall gentleman you have mentioned, why did you open one of these windows and look out soon after Bates went to the post?"
Theydon flushed like a schoolboy caught by a master under circumstances which youth generally describes as "a clean cop."
"How on earth do you know I looked out?" he almost gasped.
"I'll tell you willingly. The discovery was Mr. Furneaux's, not mine. When we came here this morning, and ascertained that you had been out at a late hour last night, we asked your man if he could enlighten us as to your movements. He did so. To the best of his belief you dined at a club, and occupied a stall at Daly's Theater subsequently. He was sure, too, you had not walked home through the rain, so it was easy to draw the conclusion that you returned in a covered vehicle. Mr. Furneaux requested Bates to produce the clothes you had worn, which, owing to the uproar created by the news of the murder, had not been brushed and put away. As a consequence the silk collar and part of the back of your dress-coat bore the marks of raindrops. How had they got there? The only logical deduction was that you had thrust your head and shoulders through a window, and the time of the action is established almost beyond doubt, because you had changed the coat when Bates came from the pillar-box. It was either directly after you came in, or while Bates was absent. Of course you may have looked out twice. Did you? Whether once or twice, why did you do it?"
Theydon's feelings changed rapidly while Winter was delivering this very convincing analysis of a few simple facts. He had passed at a bound from the detected schoolboy stage to that of a man forcing his way through a thicket who finds himself on the very lip of a precipice.
He remembered hazily that Bates had said something at Waterloo with regard to the manner in which the detectives, especially Furneaux, had questioned him. But it was too late to apply the warning thus conveyed. If he faltered now he was forever discredited. These men would read his perplexed face as if it were a printed page. In his distress he was prepared to hear Winter or that little satyr, Furneaux, say mockingly:
"Why are you trying to screen James Creighton Forbes? What is he to you? What matter his fame or social rank? We are here to see that justice is done. Out with the truth, let who may suffer."
But neither of the pair said anything of the sort. Furneaux only interjected a sarcastic comment.
"You will observe, Mr. Theydon, that even in a minor instance of deductive reasoning, such as this, the man who smells rather than the man who smokes tobacco solves the problem promptly."
Theydon threw out his hands in token of surrender. He thought he saw a means of escape, and took it unhesitatingly.
"I'm vanquished," he