a steel splinter into a man's stomach when you're miles away from the scene."
"You rig up a death trap," I said, "using a keyhole."
"Now, look, we went over all that before. The key was inside the keyhole when we broke in, I told you that, and I won't believe the killer used some kind of tricky gimmick that the lab crew overlooked."
"That's not what happened at all. What hung both of us up is a natural inclination to associate the word 'keyhole' with a keyhole in a door. But the fact is, there are five other keyholes in this room."
"What?"
"The desk, Eb . The roll top desk over there."
He swung his head around and looked at the desk beneath the window. It contained five keyholes, all right—one in the roll top, one in the center drawer and one each in the three side drawers. Like those on most antique roll top desks, they were meant to take large, old-fashioned keys and therefore had good-sized openings. But they were also half-hidden in scrolled brass frames with decorative handle pulls; and no one really notices them anyway, any more than you notice individual cubbyholes or the design of the brass trimming. When you look at a desk you see it as an entity: you see a desk.
Eberhardt put his eyes on me again. "Okay," he said, "I see what you mean. But I searched that desk myself, and so did the lab boys. There's nothing on it or in it that could be used to stab a man through a keyhole."
"Yes, there is." I led him over to the desk. "Only one of these keyholes could have been used, Eb . It isn't the one in the roll top because the top is pushed all the way up; it isn't any of the ones in the side drawers because of where Murray was stabbed—he would have had to lean over at an awkward angle, on his own initiative, in order to catch that steel splinter in the stomach. It has to be the center drawer then, because when a man sits down at a desk like this, that drawer—and that keyhole—are about on a level with the area under his breastbone."
He didn't argue with the logic of that. Instead, he reached out, jerked open the center drawer by its handle pull and stared inside at the pens and pencils, paper clips, rubber bands and other writing paraphernalia.
Then, after a moment, I saw his eyes change and understanding come into them.
"Rubber band," he said.
"Right." I picked up the largest one; it was about a quarter-inch wide, thick and strong—not unlike the kind kids use to make slingshots. "This one, no doubt."
"Keep talking."
"Take a look at the keyhole frame on the inside of the center drawer. The top doesn't quite fit snug with the wood; there's enough room to slip the edge of this band into the crack. All you'd have to do then is stretch the band out around the steel splinter, ease the point of the weapon through the keyhole and anchor it against the metal on the inside rim of the hole. It would take time to get the balance right and close the drawer without releasing the band, but it could be done by someone with patience and a steady hand. And what you'd have then is a death trap—a cocked and powerful slingshot."
Eberhardt nodded slowly.
"When Murray sat down at the desk," I said, "all it took was for him to pull open the drawer with the jerking motion people always use. The point of the weapon slipped free, the rubber band released like a spring, and the splinter shot through and sliced into Murray's stomach. The shock and impact drove him and the chair backward, and he must have stood up convulsively at the same time, knocking over the chair. That's when he staggered into those bookshelves. And meanwhile the rubber band flopped loose from around the keyhole frame, so that everything looked completely ordinary inside the drawer."
"I'll buy it," Eberhardt said. "It's just simple enough and logical enough to be the answer." He gave me a sidewise look. "You're pretty good at this kind of thing, once you get going."
"It's just that the pulp connection got my juices flowing."
"Yeah, the pulp connection.