He made two stops for fuel, one at a crowded motorway services and the other at a quieter countryside station where he popped the bonnet and retrieved his Browning and ammunition, which he tucked under the driver’s seat. The rest of the way, he stayed sharp by burning through two packs of Gauloises and forcing himself to keep mentally revisualising the video footage Saunders had made him watch. The combination of fear and nicotine made for a powerfully stimulating cocktail that impelled him to cover the fifteen hundred kilometres like a racing driver on amphetamines and shave nearly ninety minutes off his estimated journey time.

It was just gone 9.45 p.m. when he arrived in Albarracín. Every mile of the way, the same nagging voice at the back of his mind hadn’t stopped telling him how thin his lead was. If he was on the wrong track, he had no idea what to try next. He felt nauseous with worry and exhaustion and badly needed to sleep a while, but couldn’t stop moving or shake from his mind the image of Saunders’ spooks shadowing Grace, ready to step in and put a bullet in her head if he failed in his quest.

He parked the Alpina in a quiet layby on the edge of Albarracín, took out his phone and a notepad and pen, and got to work using Google Maps to put together a list of all the hotels, boarding houses and guest houses in the town and the surrounding area. The sure knowledge that his target would have been travelling incognito gave him nothing to go on, except for Wolf’s picture. It meant that he’d have to do this the hard way, hoofing it from hotel to hotel with some pretext for showing the picture to people in the hope that someone might recognise it and point him in the right direction. With his list complete, Ben sat staring at it for a long time before he felt a stabbing ache in his temples and realised that this wasn’t the right approach. He ripped the page from the notepad and crumpled it. Then reclined into the driver’s seat, closed his eyes and tried to let his mind take a step back.

To catch a wolf, you have to think like a wolf.