Grace sighed and rested his hands in his lap. “No, you’re it. We’re trying everything else we can, I promise. There are people on the phones right now, chasing every half-assed thing they can think of. But it’s not going to work—not in time. So it’s down to you. I’m sorry, but it is.”

Dryden stared out into the darkness below, and thought of the Hail Mary plan again—the reason they were going to Ashland. It rested on an idea—an awkward fact the American intelligence community had started running into, a few years back:

Some of their nullified witnesses from decades ago—the people who’d had their memories scrubbed with those drugs—had ended up remembering a thing or two. Sometimes a lot more than that.

The first known case was a man named Kurt Reyher, an East German intel officer who defected to the United States in 1967. He escaped by meeting with American agents inside the Bode Museum in East Berlin, who then smuggled him out of the country. They brought him stateside and the CIA spent two months interviewing him, learning everything they could. Then they used the drugs to blank out his memory of that time, so he would never know exactly what he’d revealed, or who’d questioned him. That was a precaution in case his own people ever got him back. But they didn’t get him back. He settled in a suburb outside Houston and got married and had two kids, and everything was fine—until one day in 2008, when he and his wife were vacationing in Berlin, and they decided to check out the Bode Museum. The moment Kurt Reyher set foot in that place, the memories started coming back—vague at first, and then vivid.

As far as we can tell, Grace had said, it was the setting that did it: being back inside that place, which hadn’t changed much in all the years since he was there.

The museum, with its distinct look and feel—maybe even its smell—had pulled up Reyher’s memories like a salvage tug hauling part of a shipwreck out of the murk.

Which meant the nullification drugs probably didn’t erase memories at all—they just buried them under a ton of silt. And if you could get a hold of something down there and pull it up, you might bring a lot more with it. In Kurt Reyher’s case, he eventually recalled the names of the operatives who’d helped him escape East Germany, and some of those who’d interviewed him afterward. All those lost memories were tied together, like the hubs and spokes of a Tinkertoy assembly.