Tanner thought for some moments.
“I’d like to oblige both you and Miss Drew,” he said, “but I’m not just sure that I ought. However, as you say, it’s not exactly on the case, and if you give me your word to keep the thing to yourself I’ll tell you.”
“I promise most gratefully.”
“Very well. The man has an alibi,” and Tanner repeated Cosgrove’s story of the visit to Montrose, the missing of the , the return to his rooms, the call at the theatre on Miss Belcher, and the final journey north by the . Then he explained how he had checked Cosgrove’s statements, and produced his calculation of times and distances, showing that Cosgrove could not have motored to Luce Manor.
To Daunt the whole thing seemed utterly conclusive. Apart from the mere fact that it had satisfied Tanner—no mean test—he could not himself see any possibility of a flaw. With considerable apprehension of the disappointment Lois would feel, he telephoned to her and arranged their consultation for that evening.
She heard his story almost in silence. But she did not show the chagrin he expected.
“If the thing was obvious,” she said in answer to his comment, “Cosgrove would have been arrested and not Austin. But I feel absolutely certain that that alibi of Cosgrove’s is a fraud. He has tricked Inspector Tanner. How he has done it is what you’ve got to find out.”
“My dear girl,” Daunt remonstrated, “it’s all very well to talk like that, and I’ll do my best of course, but you know, if Tanner with all his opportunities was taken in, it’s not too likely I shall find the flaw.”
“It’s quite likely,” she declared. “Inspector Tanner was not specially looking for a flaw; you are. Don’t you see—there must be a flaw. Look at it like this. A man resembling Austin was met by Sir William at the boathouse on that night. It must have been Cosgrove, because no one else is sufficiently like Austin to be mistaken for him. No kind of facial makeup will meet the case, because Sir William himself evidently was satisfied. Therefore Cosgrove’s alibi must be false. Don’t you agree with me?”
“It seems reasonable,” Jimmy admitted. “But the alibi certainly looks right enough too.”
“I admit that. It may be so good that we’ll never find the flaw. But we must try. Oh, Jimmy,” she turned to him beseechingly, “remember what is at stake—his life—both our lives. You will try, won’t you?”
“Of course I’ll try, and what’s more, I expect to succeed,” Jimmy lied bravely. And he spoke in the same confident tone as, after dinner, he went to the station with her, and saw her off by the to Halford. But his secret feelings were very different.
Two days later he had another call from Lois.
“You needn’t be frightened,” she smiled at him; “I am not going to haunt the office and make your life a burden to you. But I have been thinking over our problem. I want you, Jimmy, to begin an investigation. Will you?”
“Why certainly, if I can. What is it?”
“If you haven’t time yourself, and I don’t expect you will have, employ a private detective. But get a good man who will do the work thoroughly.”
“Yes, yes. But what exactly is to be done?”
“This. The evidence seems to me overwhelming that Mr. Cosgrove missed the at King’s Cross on that night, and went to Montrose by the . But what did he do in between?”
Daunt was puzzled.
“I don’t understand,” he said. “We have the butler’s and Miss Belcher’s evidence to corroborate Cosgrove’s own story there. I don’t see that we can reasonably doubt he did what he said.”
“Don’t you? But I do. Probably both these people were interested. Miss Belcher we know was—she was on too friendly terms not to be. And the butler may have been well paid to tell his story. Another thing makes me doubt Miss Belcher. You remember the conversation Mr. Tanner overheard between her and Mr. Cosgrove in the restaurant? They mentioned an alibi. Mr. Tanner thought they were talking about Austin. I don’t believe it. It was Mr. Cosgrove’s own alibi they were discussing. What do you think?”
“It’s possible, of course,” Daunt answered slowly, “but I question if we can be sure of it.” He began to think Lois had got an obsession.
“Well, whether or not is immaterial. What matters is that Mr. Cosgrove’s whereabouts after has not been proved.”
“But you forget Tanner’s time table. Cosgrove wouldn’t have had time to go to Luce Manor between the trains.”
“Yes!” cried Lois excitedly, “he would! That’s the point I’ve been coming to. According to Mr. Tanner’s calculations he would have had time or almost time, to go to Luce Manor and back, but he wouldn’t have had time to commit the murder. But Mr. Tanner assumed he had first driven to his rooms. If he had gone direct from King’s Cross he would have had time for all.”
This was a new idea to Daunt, and he had to admit its possibility.
“It may be so certainly,” he answered, “but how are we to prove it? That butler won’t give himself away if he has lied.”
“I’ve thought of that, too, and there seems to be one way we might get at it. Mr. Cosgrove said he took three drives during that time—first, from King’s Cross to Knightsbridge; second, from Knightsbridge to the Empire; and third, from the Follies’, to King’s Cross. Could we not find the cabmen, or at least one of them?”
“By Jove, Lois, you should have been a detective,” Daunt said with half-unwilling admiration. “I believe it’s a good notion.”
“You see, if we were to search for these men thoroughly and fail to
