Tom stopped and squatted down in a show of tying his shoelace, but more to have the opportunity to assess Martin from behind at a slightly longer distance. Was it just his imagination that there was a slight disturbance in the suit’s line at the back? Was that a small bulge in the base of his spine? A pancake holster? Tom knew for a fact that witness protection officers were not armed, instead availing themselves of SCO19—the specialist firearms unit—when required.

Tom wondered if he was being paranoid, but thought the consequences through quickly.

Martin turned, suddenly aware that Tom was no longer next to him, a slightly impatient look showing in his light-blue eyes.

‘We must get a move on,’ he said, the slight but familiar accent barely discernible but ringing further alarm bells in Tom’s mind. It was time to act; no turning back.

Martin moved to the front passenger door, opening it for Tom as a chauffeur would, jerking his head towards the leather seat.

Tom shrugged his grab-bag from his back and went to the rear passenger door, opening it and casually throwing the bag on the rear seat. He slammed the door while mentally preparing his next move, knowing he probably only had one chance. Martin was a big guy and Tom instinctively knew he would be problematic without the element of surprise.

Tom shaped his body as if to lower himself into the Audi passenger seat. As he did so, Martin turned to cross in front of the car to the driver’s seat. Tom raised his right hand in a club fist and drove it hard, four inches below the big man’s ear, smashing into the vagus nerve chain. Martin’s knees buckled, and he hit the floor in a crumpled heap.

It was serious now. If Tom was wrong, he would be in big trouble for knocking out a colleague. But he was certain he wasn’t. He searched the man’s pockets and found that his instincts had been correct. Under his left armpit was a handgun, secured in a concealed holster.

Tom looked at the Sig Sauer P226. Not police issue, certainly not with the silencer attached to the front: an assassin’s weapon. With the subsonic ammunition that Tom was willing to bet the weapon was packing, it was very quiet. The 9mm round it fired was designed, even at low speeds, to bounce around inside the body, ricocheting off bones but staying inside, causing maximum damage.