Bell frowns at his sandwich. “Everything I’ve read—”

“Are you talking about police investigation manuals? They’re focused on sexually motivated homicide, and they’re all based on Psychopathia Sexualis, which was written in the goddamn nineteenth century. So everything you’ve read is wrong, or out-of-date, or both. It’s not about sex. At all.”

Bell scowls. “So what’s it about, then? What would make a teenager like McMurtry kill three elderly women and jerk off over the bodies?”

“It’s about exerting power. McMurtry was browbeaten—and physically beaten—by his elderly aunt from early childhood. Instead of focusing his rage on her, he went out and murdered three other women of a similar age. He had no power with his aunt, so he exerted power over three proxies. Feeling that kind of power is thrilling, and he got turned on by it. End of story.”

“Every case is different,” Bell insists.

“No. Every case is the same.” She leans forward, because she wants him to understand. “Power. Domination. Control. Manipulating the people around you, fooling them into thinking you’re normal. The smarter ones cover their tracks better, and they’re better at the manipulation part, which makes catching them harder. That’s it. That’s all there is. So why are we doing this? With these interviews?”

“To be thorough? The FBI interviewed all the others. They want to see if there’s anything different in the younger ones.”

“And do you think there is?”

“Hard to tell from one sample.” He looks at her over the top of his cup. “But you don’t think there will be.”

“I’m expecting to see five guys who are either dumb or unlucky.”

“Which category does McMurtry fall into?” Bell snorts, shakes his head. “No, don’t answer.”

“Eat your sandwich,” Emma suggests. “It’s getting cold.”

Once Bell has finished demolishing his food, he goes out and gases up the truck while Emma pays. The light outside makes blue-gray shadows in the parking lot, and the smell of exhaust off the interstate is strong. Emma feels like she’s a thousand years old. She turns, searching out the last rays of the sun, before she climbs back into the cab.

She buckles up. “I signed on to this because I told myself we’d be gathering new information, that we’d be learning something.”

“We are,” Bell insists.

“I don’t know. And I don’t understand Cooper’s motivation. Why now, when he’s so busy with whatever’s happening in Pennsylvania? You said that case is a big deal, right?”

Bell’s voice is stiff. “They’re talking on the news about curfews for teenagers, so yeah, it’s a big deal.”

“And Cooper is heading up that investigation unit. He’s right in the thick of it. So again, I’m wondering why he’s suddenly so interested in all of this.”

Bell doesn’t seem to have an answer. They merge onto the main road before he speaks further. “If you don’t think we’re doing anything useful with these interviews, why’d you join up?”

Emma hedges. “I didn’t say it’s not useful. Every piece of information is useful.”