Knox stood paralysed, staring at the destruction. He reached for his chest and felt the bundle of papers that were still in the inside pocket of his jacket. He knew this wasn’t an accident. He didn’t know if the fire had been meant to burn him and the papers along with his flat, or if it was some kind of swift retribution for the death of the man in Stockholm. But either way someone was sending him a very direct message.

He wanted to push past the gawpers and see just how much damage had been done, but he knew that if he did, or even if he just stayed on Berwick Street much longer, anyone waiting to make sure he got the message would spot him. And he didn’t have enough energy to cope with whatever else they might want to throw at him.

He turned away from Kemp House and slipped into D’Arblay Street. He hugged doorways as he moved quickly across Wardour Street and through the narrow cut-through of St Anne’s Court, before doubling back north up Dean Street and into Soho Square.

He paused at the edge of the old public garden, watching the corner he’d just turned around. After a moment a figure appeared, lingering on the kerb. It was a man, wearing a heavy mackintosh. His face was obscured by the umbrella he was still holding up even though the last of the rain had stopped falling. He may have just been a drunk businessman trying to decide which way to take home, but after he’d spent almost a full minute looking up and down Dean Street and towards Soho Square, Knox decided he was trying to do something else.

Knox was tired of being watched, followed, and attacked. But he was also physically exhausted. He decided that right now his best course of action was to retreat. He waited for the man to turn away from the square, then he burst into a run, leaving his hiding place in the shadow of a large old plane tree and making a break for Tottenham Court Road.

The tube station was shut, the last train gone. But there were two double-decker night buses idling on the north side of the station’s New Oxford Street entrance. The first bus started its engine as Knox reached it, and pulled away just as he jumped on its backboard.

His respite lasted twenty seconds until the second bus also started to move down New Oxford Street, apparently taking an identical route. There was a chance the man looking for Knox had missed his quick, echoing footsteps around Soho Square and had been too slow off the mark to catch the bus behind him. But after what Knox had gone through over the last twenty-four hours he wasn’t inclined to hope.