Dryden took his eyes off the road for a second and studied the pile. The sheet on top wasn’t the first page—everything had gotten scrambled when he’d gathered the stack together—but it looked like all the others he’d seen in those few seconds at the bottom of the stairs: typewritten text, double-spaced, just enough distortion to show that it had been photocopied from some original source material. The stack of pages added up to a single thick document.

The visible page was covered with redaction marks, blotting out easily half the text in bits and pieces, all over the sheet. The whole document was probably like that.

Of the text that remained clear, Dryden had read almost nothing. There hadn’t been time.

Danica was still looking at him. Waiting.

“I don’t know its details,” Dryden said. “But I know what it is. I know what kind of document it is.”

He reached over and tapped the very top of the page, where a string of text made up a header. He’d seen the same line at the top of every sheet:

WITNESS NULLIFICATION [C43-YANKEE]—PERSONS 2855 & 2856

“It’s called a scrub file,” Dryden said. “I’ve heard of them, but I’ve never seen one myself until now. I wasn’t sure they really existed.”

“What’s a scrub file?”

Dryden thought about it. There were only so many ways to say it. There was only so much he knew in the first place.

“Jesus,” he whispered. It was still hitting him—the gravity of the thing. And what it must mean, in terms of what they were involved in here.

Danica watched him.

“I used to be in the military,” Dryden said. “I heard about scrub files and witness nullification back then, but only as old stories, rumors. It was something the government used to do, way back. Cold War stuff. They quit doing it long before I was ever in the service.”

“But what was it?”

“It was a way of dealing with people who accidentally learned things they weren’t supposed to … when you couldn’t justify killing them. Like innocent bystanders who happened to see something classified. The textbook version I always heard about went like this: what if there was a fire at some civilian office building that was actually a CIA safe house? What if local firefighters showed up and went in, before the government could secure it, and what if they saw something that had to stay secret, at all costs? What are you supposed to do, kill them? Kill people who were just doing their job?”

Danica looked down at the stack of papers. She ran a fingertip over the header line.

“Witness nullification,” she said. “How did it work?”