“Very well, sir. After I left you in the garden this morning, I asked them all—the household—some more questions, and elicited the fact that one of what you called the ‘cast-iron’ alibis was a dud, so to speak. It was like this, sir: one of the maids had told me she’d seen Mr. Deacon—that’s the deceased’s secretary—go to his room just after ten. That coincided with what he told me himself, and also with what Sir Arthur Digby-Coates said. Now, this girl spent the time from ten until about a minute before the murder was discovered working—arranging things and what not, I take it—in the linen-room. Apparently it took her so long because she’d been behindhand, so to speak, and was doing two evenings’ jobs in one. This linen-room’s just opposite Mr. Deacon’s room, and the girl said last night that she knew he hadn’t come out because, having the door of this linen-room open all the time, she couldn’t have helped but see him if he had. “But she told a different tale this morning, sir, when I talked to her after you’d left me. I wasn’t thinking about Deacon at all, to tell you the truth, when out she comes with something about having made a mistake. ‘What’s that?’ I said, and told her not to be nervous. Then she tells me that she hadn’t been in the linen-room all that time after all. She’d left it for about ten minutes to go downstairs. She was very upset—seemed to think we’d think she was a criminal for having made a slip in her memory.” Boyd laughed. Anthony did not. “What time was this excursion from the linen-closet?” he asked. “As near as the girl can remember, it was ten minutes or so after she saw Deacon go into his room, sir.” “And I suppose, according to you, that this Deacon left his room while the girl was away, slipped out of the house, waited, climbed into the study window, killed his employer, climbed out again, hid somewhere till the fuss was over, got back unseen to his room, and then pretended he hadn’t ever left it.” Boyd looked reproach. “You’re being sarcastic, sir, I know; but as a matter of fact that’s very nearly exactly what he did do.” “Is it? You know, Boyd, it doesn’t sound at all right to me.” “You won’t think that way, sir, when I tell you that we _know_ Deacon’s our man.” Boyd lowered his voice. “Colonel Gethryn, those finger-prints on the weapon—the wood-rasp—are Deacon’s!” “Are they now?” said Anthony irritably. “How d’you know? What did you compare ’em with?” Boyd looked at him almost with pity. “Got every one’s marks this morning, sir.” He smiled happily. “Handed each one of ’em—when I was alone with ’em, of course—a bit of white paper. Very mysterious I was about it too, asking ’em if they recognised it. They didn’t: very natural when you come to think each sheet was out of my notebook.” He looked again at his watch. “One moment,” said Anthony. “Found anything like a motive?”