“Oh! That’s the neatest thing of all. And delightfully simple, although it took me a minute or two to discover it after I’d seen the footprint. Look! You see this handle, the ordinary type for this sort of window. It consists of an arm that fits into the lock and a heavy handle set at right angles to it, the whole moving on a central pivot; the weight of the handle end keeps the other end in position. Well, watch!” Carefully arranging the handle so that the heavy end was balanced exactly above the pivot, Roger pushed the window sharply back into its frame. Immediately the handle was dislodged by the jar, and, with a little click, the fastener fell into place in its socket, the weight of the falling handle driving it well home. “Well, I’m dashed!” Alec said. “Neat, isn’t it?” Roger said proudly. “He stood on the sill outside, you see, and pulled it to behind him, having fixed the handle in position before he got out. I suppose it’s a trick you could play with any lattice window, though I’ve never come across it before.” “That’s one to you, all right,” said the humbled Alec. “I take back quite a lot of the unkind things I’ve said to you.” “Oh, don’t trouble to apologise,” Roger said magnanimously. “Though I did warn you that I should turn out to be right in the end, you remember. Well, I don’t think you’ll trouble to dispute the fact of murder any more, will you?” “Don’t rub it in,” Alec protested. “I did it for the best, like the doctor in the poem. Well, what’s the next move?” “Let’s go out and have a look at that footprint at close range, shall we?” Roger suggested. “There might be some others, too. Footprints! We _are_ getting professional, aren’t we?” On a more careful inspection the footprint fully bore out Roger’s contention that it must have been made by a man stepping backward from the sill. The heel end was nearly an inch and a half deep; the toe scarcely half an inch. The edges were slightly blurred where the earth had crumbled, but the mark was clearly that of a large foot. “At least a ten boot,” Roger said, stooping over it. “Possibly eleven. This may be very useful indeed, Alec.” “It’s a bit of luck, certainly,” Alec agreed. Roger straightened up and began to search among the plants near the edge of the bed. After a moment he dropped on his knees on the grass border. “Look!” he exclaimed excitedly. “Here’s another!” He parted two little shrubs and peered between them. Alec saw another footprint, not so deep as the last, but quite plainly marked in the dry earth. The toe of this one was also pointing towards the window. “Same fellow?” he asked, bending over it. “Yes,” Roger replied, examining the print intently. “The other boot. Let’s see, this is well over a yard from the last one, isn’t it? He must have stepped back on to the path in two big strides.” He rose to his feet and dusted the knees of his trousers. “It’s a pity we can’t track him any farther,” he added disappointedly.