She chose a package that held three devices constructed of lead, heavy steel cable, and plastic sheathing. The lead was a thick wedge at the end of a cable perhaps one quarter inch thick. This looped through the wedge at one end and also formed another loop at the other end. In the middle was a tough plastic sheath, which wrapped tightly round the cable and thus held the two sides of it closely together. The result was a sturdy cord with a slug of lead at one end and a loop at the other.
“This,” Hannaford said to Lynley, “is a chock stone. D’you know how it’s used?”
Lynley shook his head. Obviously, it was meant for cliff climbing. Equally so, its loop end would be used to connect the chock stone to some other device. But that was as much as he could sort out.
DI Hannaford said, “Hold up your hand, palm towards yourself. Keep your fingers tight. I’ll show you.”
Lynley did as she asked. She slid the cable between his upright index and middle fingers, so that the slug of lead was snug against his palm and the loop at the other end of the cable was on her side of his hand.
She said, “Your fingers are a crack in the cliff face. Or an aperture between two boulders. Your hand is the cliff itself. Or the boulders themselves. Got it?” She waited for his nod. “The lead piece?that’s the chock stone?gets shoved down the crack in the cliff or the aperture between the boulders as far as it can go, with the cable sticking out. In the loop end of the cable”?here she paused to scan the wall of climbing gear till she found what she wanted and scooped it up?“you clip a carabiner. Like this.” She did so. “And you fix your rope to the carabiner with whatever sort of knot you’ve been taught to use. If you’re climbing up, you use chock stones on the way, every few feet or whatever you’re comfortable with. If you’re abseiling, you can use them at the top instead of a sling to fix your rope to whatever you’ve chosen to hold it in place while you descend.”
She took the chock stone from him and replaced it along with the carabiner on the wall of goods. She turned back and said, “Climbers mark each part of their kit distinctly because they often climb together. Let’s say you and I are climbing. I use six chock stones or sixteen chock stones; you use ten. We use my carabiners but your slings. How do we sort it all out quickly and without discussion in the end…? By marking each piece with something that won’t easily come off. Bright tape is just the ticket. Santo Kerne used black electrical tape.”
Lynley saw where she was heading with this. He said, “So if someone wishes to play fast and loose with someone else’s kit, he merely needs to get his hands on the same kind of tape?”
“And the equipment itself. Yes. That’s right. You can damage the equipment, put identical tape over the damage, and no one is the wiser.”
“The sling, obviously. It would have been the easiest to damage although cutting it would have shown, if not to the naked eye, at least to the microscope.”
“Which is exactly what happened. As we’ve discussed earlier.”
“But there’s more, isn’t there, or you wouldn’t have shown me this.”
“Forensics went through Santo’s kit,” Hannaford said. Hand on his elbow again, she began to guide him out of the shop. She kept her voice low. “Two of the chock stones had been seen to. Beneath the marking tape, both the plastic sheathing and the cable had been damaged. The sheathing was cut through; the cable was hanging on by a metaphorical thread. If the boy used either one for an abseil, he was done for. Same thing applied to the sling. He was a dead man walking. A dead climber climbing. What you will. It was only a matter of time before he used the right piece of equipment at the worst possible moment.”
“Fingerprints?”
“Galore,” Hannaford said. “But I’m not sure how useful they’re going to be since most climbers don’t go solo all the time, and we’re likely to find that’s the case with Santo.”
“Unless there’s a print on the damaged pieces that doesn’t exist on any others. That would be difficult for someone to explain away.”
“Hmm. Yes. But that whole bit has me wondering, Thomas.”
“What whole bit is that?” Lynley asked.