paint over the cuts shows that he wished to hide his work as much as possible. Finally, the incision is right up under the top piece.â
âYes, but that doesnât hide it when you look up from the floor.â
âIt is in the shadow cast by the overlap of the board above. But he had a second reason for putting the opening as high as he could, his real reason. He needed it to be flush with the underside of the top board.â
âBut what about the other opening on the other side?â
âItâs a blind.â
âOh, you canât get rid of additional facts that donât support your theory by dismissing them as lead-away false clues.â
âWell, now weâll get to the center, and that will show. Weâve simply been looking at the not very communicative mouth.â
Dr. Wendover knelt down and the Sergeant followed suit. The pocket flashlight threw its bright circle on the underside of the top board of the ladder.
âNot much there.â A grumbling tone was coming back into the Sergeantâs voice. The bright circle traveled along the grain of the wood.
âThose little indentations,â the Doctorâs voice said beside him. âA couple here; another couple here; a third pair here; and now â¦â the light dipped down some four inches and retraced its course. âYou see the same little indents and, now, as we reach the end, by what I have called the blind mouth on the ladderâs right side, a final couple of these same small punctures.â
âWell, there may have been some bit of upholstery or mat tacked onto the top step so you could kneel on it safely without danger of its slipping.â
âQueer, then, that there is no pair of punctures on this left-hand side.â
âOh, this is altogether too fine-drawn, Doctor!â
âWe are dealing with something very fine,â he allowed, âbut, really, no finer than a fingerprint. This is a very clear and telling impression.â
As they rose from their knees and he slipped the torch back into his pocket, he took out a pad and pencil. âLetâs chart those punctures like a graph.â He plotted them on the paper. âSee, they werenât quite parallel: while on the right side, where the two lines most diverged, they were closed by that last couple of indents and, on the left side, where they are closest, there is no closing brace of punctures.â He rapidly drew connecting lines through the points he had plotted.
Sergeant Skillin, looking over his shoulder, remarked, âWell, they might be the marks of the tacks that held on a cloth cover, as Iâve said. You see, since the person was so unskillful as not to keep his lines straight, theyâd diverged at the right side, so that he had to put in an extra pair of tacks.â
âBut if he wasnât unskillful?â asked Dr. Wendover. âIf that design follows very carefully a pattern? Then, Skillin, does that pattern suggest anything to you?â
âIt looks like an elongated horseshoe pointing to the left.â
âYes. And by your insight, by your reading the writing punctured on this panel, you have got your man.â
Sergeant Skillin was quite pleased at the praise, even more doubtful of the statement, and completely puzzled at the demonstration. So he naturally said nothing.
âYes,â went on Dr. Wendover, stretching himself. âTake a chair, Sergeant. Thought contracts the muscles, do what we will. Well, itâs over. We can relax. Weâve time. Smirke was so clever that heâs quite at his ease. He wonât move till you come for him, and then heâll go quiet, certain you canât know, or if you suspect, canât prove. All we have to do now, as I suspect youâve seen through to the end, is to make certain that the jury has as clear a view as we. Youâre undoubtedly right-that almost-closed curve, plotted by those pairs of punctures on