Thistle puts on her coat. ‘Fine. Let’s go.’

Down the staircase, out the door to the parking lot. Thistle unlocks a white Crown Vic. Different plates from her last one, sleeker interior. The FBI bought thousands of these when Ford discontinued them. No CD player in this one. I’m sure Thistle is missing it—she’s a musician.

I open the case file, but it’s hard to focus, knowing the information I need won’t be in there.

Why were you naked in the woods, Biggs? The only mark on your body came from me, so who or what killed you, and how? And what the hell do I do now?

Maybe Biggs ate some poisonous mushrooms out in the woods. He could have been starving, or, since he was a pot user, maybe he thought they were hallucinogenic. I didn’t see or smell any vomit, but maybe he kept them down. Do poisonous mushrooms make you feel hot, so you take off your clothes? I don’t know. It’s strange that he was so close to the road. He didn’t get far at all before something happened to him.

I’ve been chewing my nails—now my hand freezes halfway to my mouth. If Biggs did eat toxic mushrooms, it’s possible that I poisoned myself when I bit him. I remember hearing that certain types of mushrooms—death caps, they’re called—cause your DNA to unravel. Your body withers away as though under attack from the world’s most aggressive cancer.

That would serve me right.

Thistle doesn’t speak as she drives us towards Braithwaite University. The silence is tense, but it gives me some time to scan the file. Biggs was an associate professor of mathematics who’d worked at the university for twelve years, tenured after seven. Before that he was a high school math teacher in Tennessee. He was fifty-one. Briefly hospitalised a couple of years ago, though the file doesn’t say what for. Gabriela, his wife, is a forty-eight-year-old warehouse manager. His daughter, Hope, dropped out of college to do graphic design jobs for a bank on Lamar Street. She mostly works from home. They all live together in Southampton. I can’t see any red flags, other than a professor’s daughter being a dropout.

‘Anyone else gone missing from the university?’ I ask.

‘A young woman named Abbey Chapman vanished, but that was about seven months ago,’ Thistle says. ‘And five weeks back an early-morning jogger was assaulted on a bike path near the campus.’

‘A teacher?’

‘No. Unconnected to the college, although he said the three perps—all men—looked young. Might have been students screwing around. They punched him in the head, took his phone, ran off. He couldn’t describe them well enough for us to ID them.’

‘How many students at the college?’