“And,” added Vance ironically, “his name means ‘sparrow.’ Quod erat demonstrandum.—No, Sergeant; it’s much too easy. It works out like a game of Canfield with the cards stacked; whereas this thing was planned much too carefully for suspicion to fall directly on the guilty person.”
“I can’t see any careful planning about it,” persisted Heath. “This Sperling gets sore, picks up a bow, grabs an arrow off of the wall, follows Robin outside, shoots him through the heart, and beats it.”
Vance sighed.
“You’re far too forthright for this wicked world, Sergeant. If only things happened with such naïve dispatch, life would be very simple—and depressin’. But such was not the modus operandi of the Robin’s murder. First, no archer could shoot at a moving human target and strike just between the ribs over the vital spot of the heart. Secondly, there’s that fracture of Robin’s skull. He may have acquired it in falling, but it’s not likely. Thirdly, his hat was at his feet, where it wouldn’t have been if he had fallen naturally. Fourthly, the nock on the arrow is so bruised that I doubt if it would hold a string. Fifthly, Robin was facing the arrow, and during the drawing and aiming of the bow he would have had time to call out and cover himself. Sixthly. . . .”
Vance paused in the act of lighting a cigarette.
“By Jove, Sergeant! I’ve overlooked something. When a man’s stabbed in the heart there’s sure to be an immediate flow of blood, especially when the end of the weapon is larger than the shaft and there’s no adequate plug for the hole. I say! It’s quite possible that you’ll find some blood spots on the floor of the archery-room—somewhere near the door most likely.”
Heath hesitated, but only momentarily. Experience had long since taught him that Vance’s suggestions were not to be treated cavalierly; and with a good-natured grunt he got up and disappeared toward the rear of the house.
“I think, Vance, I begin to see what you mean,” observed Markham, with a troubled look. “But, good God! If Robin’s apparent death with a bow and arrow was merely an ex-post-facto stage-setting, then we’re confronted by something almost too diabolical to contemplate.”
“It was the work of a maniac,” declared Vance, with unwonted sobriety. “Oh, not the conventional maniac who imagines he’s Napoleon, but a madman with a brain so colossal that he has carried sanity to a, humanly speaking, reductio ad absurdum—to a point, that is, where humor itself becomes a formula in four dimensions.”
Markham smoked vigorously, lost in speculation.