His instinct had been right. Three men had entered the swimming pool: an older man, a young guy who looked like a bodybuilder and some poor bastard with a canvas bag over his head and his hands tied behind his back. At that moment Hansi knew that three men had come in, but only two would be going out. He had watched them through the semi-circular window of the surviving half of what had been double doors. The younger guy, a gun in one gloved hand and a flashlight in the other, had made his way over to the door. Hansi had only just made it, skipping back, carefully making sure he didn’t stumble or make a noise on the rubbish-strewn floor, and ducking into the remnants of a cubicle. The younger man swept the changing area with his flashlight, making sure it was clear. Hansi exhaled slowly. He heard the older guy talking and he made his way carefully back to the door. They had made the hooded guy kneel at the pool’s edge and Hansi heard him scream, ‘No!’ Then there had been a flash and a resonant thump from the gun. Hansi would have expected a brighter flash and a bigger noise, and had noticed the lengthened barrel of the gun. A silencer. There was the ringing tinkle as the discharged cartridge fell onto the cracked tiles.

The two men had seemed in no hurry as they left. It was then that Hansi had seen them do the strangest thing. On the way out they had lifted the lid from an old waste bin by the door and the younger man had dropped the gun into it. They certainly had not been worried about the murder weapon being found. A few hundred metres away was a canal that had probably already served as the depository for dozens of pieces of evidence. Dumping the gun here was inviting it to be found. And, after they left, Hansi had been only too willing to oblige.

Now Hansi had something to offer in lieu of cash. He knew the Turk’s cell phone number by heart and knew that this was the best time to catch him. Hansi stood up from the bed and donned the old ex-army coat that he wore rain or shine, summer or winter. He picked up the carefully rewrapped bundle and slipped it into one of the coat’s capacious pockets. He didn’t like the idea of carrying the gun around with him, but he knew that anything left lying around in the squat had the habit of vanishing.

Hansi went out onto the landing, down the rickety stairs and out onto the street, trying to think where the nearest un-vandalised public phone would be.

Monday 16 June, 10.05 a.m. Polizeipräsidium, Hamburg.

Fabel stood at the conference room’s cherrywood table, waiting for the others to take their places. He turned round to the incident board behind him. The board was the physical presence of the inquiry – its shape – and now it was growing in substance. There was a map of Hamburg and surrounding area, on which flag pins marked the two primary murder scenes in Hamburg and the secondary scene where Ursula Kastner’s body had been found.