“Can you do anything more with these?” Alec asked with interest. “I don’t know. We ought to take accurate measurements of them some time, I suppose. Oh, and there’s something else I should very much like to do.” “What’s that?” “Get hold of a specimen boot from every male person in the house and grounds and fit them into these prints,” Roger exclaimed, raising his voice slightly in his excitement. “Yes, that’s what we ought to do if we possibly can.” Alec was pondering. “But look here, wouldn’t you say that these footprints meant that the fellow was someone outside the house? They show him getting away from the place after Stanworth had been killed, don’t they? If the chap had been someone inside the house, why should he have troubled to get out so elaborately through the window, when all he’d got to do was to walk out by the door? After all the other things he’d done to make it look like suicide, it wouldn’t really be necessary to leave the door locked on the inside, would it?” “You mean we’re not likely to find a boot in the house to correspond with these prints?” “Not if the chap were someone from outside, no. What do you think?” “Oh, yes, I agree. I think in all probability it was someone not belonging to the household. You’re quite right about the existence of these footprints all pointing to that conclusion. But we don’t actually _know_, do we? And I believe in eliminating all possibilities, however remote. If we can get a chance to try everyone’s boots out and they don’t fit, then we know quite definitely that everybody in this house is free from suspicion of committing the crime itself; though not from suspicion of other things, by the way.” “What other things?” Alec asked interestedly. “Being an accessory after the fact. After, certainly; and not improbably before, as well, some of them. It seems to me, Alec,” Roger added pathetically, “that three quarters of this household seem to be accessories after the fact! It isn’t fair.” “Humph!” said Alec. This was trespassing upon ground which he had no wish to cover. He felt thankful that at any rate Barbara Shannon’s mysterious behaviour had not come to Roger’s ears. What would the latter have said had he heard of that? Accessory after the fact seemed mild in comparison. “Hullo! What’s up?” he asked, suddenly catching sight of Roger. That gentleman was listening intently, his head on one side. At Alec’s words he held up his finger warningly. “Thought I heard someone in the library!” he whispered. “You creep up to the lattice window and look through. I’ll try the French ones. Carefully!” Enjoying himself thoroughly, he made his way stealthily to the side of the French windows and peeped cautiously round them. He had his reward. The library door was closing softly. He hurried back to Alec. “Did you see?” he asked, in a voice thick with suppressed excitement. “Did you see?” Alec nodded. “Somebody was going out of the library,” he said. “Yes, but did you see who it was, man?”