It was at least another hour before Nightingale joined us, and I then got to watch him sink a pint of bitter while he outlined what he’d discovered—which was, as far as Nightingale could determine, that Jason Dunlop had had no contact with Geoffrey Wheatcroft while at the university.

Nightingale had at least thought to pick up a printout of every student and lecturer who’d been at Magdalen at the same time as our man Jason. Plus a list of every student who had ever attended a class by Geoffrey Wheatcroft. It added up to a stack of hardcopy of just the right size and thickness for beating a suspect without leaving a bruise—if that’s where your idea of law enforcement took you. If the data was entered into HOLMES it could be automatically crosschecked against any other names that came up during the mundane phase of the inquiry. The Murder Team under Stephanopoulis had at least three civilian workers whose only job was to do that sort of tedious, time-consuming, but totally vital kind of work. What did the Folly have? You can guess what the Folly had, and he wasn’t happy at the prospect.

Postmartin asked what Nightingale planned to do next.

Nightingale grimaced and took another pull on his pint. “I thought I’d retrieve the remainder of library cards from Ambrose House. It’s time to see where the rest of the books came from.”

NIGHTINGALE TOLD me to get off the motorway at junction 5 and we drove through Stockenchurch, which appeared to be a hospital with a rather nice village attached, before turning left onto a B-road, which quickly became a narrow lane that ran between the tall green walls of very old-fashioned hedgerows.

“A large part of the estate is rented to local farmers,” said Nightingale. “The gate is coming up on your left.”

If he hadn’t warned me I’d have overshot. The hedgerow abruptly became a high stone wall broken by a wide wrought-iron gate. I stopped the car while Nightingale got out, followed by Toby, and unlocked the gate with a big iron key. He opened the gate with a standard horror-movie creaking noise and waved me through while Toby made a point of marking the gatepost. I stopped and waited for Nightingale to get back in but he pointed to where the drive turned suddenly behind a stand of trees.

“Meet me around the corner,” he said. “It’s not far.”

He was right: I turned the corner and there was the main building of the school right in front of me. The Jag crunched to a halt on the gravel drive and I got out to have a look.