Pendergast took up the end of the rope. Nora tightened the slack and eased out the chest, letting it swing free. She steadied it with her hand.

“Ready to lower.”

Pendergast played out the rope and the chest slowly descended. When it reached the ground, Nora climbed back down, removing the pitons as she went.

The box sat in the grass, rusty but intact, with a brass padlock. “Should we break the lock?” Corrie asked.

Pendergast knelt. A pale hand slipped into his suit jacket and brought out a small, strange-looking tool. He fiddled with the lock and it clinked open.

Nora felt her heart quicken.

Pendergast opened the lid. Inside were various leather-wrapped packets; where the leather had rotted and shrunk, it revealed gleaming stacks of gold coins.

The Wolfinger treasure.

Nora stared. “I can’t believe it. There’s a thousand holes up there. We’ve been looking for weeks. And in ten minutes you point to one hole—and bingo. How?”

Closing the lid, Pendergast reattached the lock and rose. “It’s all about snow depths. You were undoubtedly correct in assuming that Spitzer and Reinhardt originally hid the chest in that six-to-twelve-foot range. But the snow kept falling and growing deeper. They still hoped to be rescued and wanted to keep close track of the gold’s precise location. So as the snow deepened and threatened to bury the gold and make it inaccessible, they moved it up. And up. They kept doing so until they became too weak to move it any further. Given that they died at the end of January, I estimated that point came early in the month, when the snow was eighteen to twenty-one feet deep. So I examined the cliff face for a hole at about that height.”

“Clever. But there are still countless holes at that level all over in these cliffs. How did you know exactly where to look?”

“I asked myself what landmark the two would have chosen—and the face of the old woman you mentioned sprang to mind. Based on what I can see at present, it must have been the only distinctive landmark. And that cliff is like Swiss cheese: if the treasure had been hidden in any other hole, it would have been very difficult to find again. Knowing that, I looked to the holes directly beneath where the old woman’s face had been situated before it fell. I saw likely holes at around eighteen, twenty, and twenty-two feet. I guessed the one in the middle. Correctly, as game theory could have predicted.”

“Jesus,” said Corrie. She turned to Nora. “Why didn’t you think of that?”

“Because she didn’t follow the logic to its bitter end,” said Pendergast. “A common human failing, even among quite intelligent people.”

He hefted the strongbox. “My goodness, what a lot of gold! And now, I think we are well and truly finished here. I suggest you arrange to get this out at the earliest possibility—perhaps by helicopter, then armored car to a suitable safe deposit vault at the Golden Pacific Bank in Sacramento.”

“Sounds like a good idea,” said Nora.

“I congratulate you both on solving this case. I understand Agent Morwood is to receive a commendation for his excellent work.” He paused with a cynical smile.

“And not Corrie?” Nora asked.

Corrie smiled ruefully. “Aloysius tells me I’m learning the ways of the Bureau.”

“Indeed. Your turn will come.”

“Can’t come soon enough.”

Pendergast looked from one to the other. “The forensic anthropologist and the archaeologist—one wonders if you two might have reason to partner on a future case?”

“Professionally?” Corrie scoffed, with an amused sideways glance at Nora. “Seems unlikely. Nora can be a real pain in the ass.”

“And you’re a short-tempered punk.” Nora turned to Pendergast. “I’m a pain in the ass? That goes double for her. We’d be at each other’s throats.”

“And that,” Pendergast replied placidly, “is precisely why such a partnership just might work.”