He drove to the Herengracht, parked two blocks from the address of the safe house, and walked the rest of the way, pulling on his gloves as he went. He made two passes of the property, the first from the opposite side of the canal to check for any obvious surveillance or activity in the vicinity, and the second by the house itself in an effort to spot lights or other signs of occupancy. No one appeared to be watching, no lamps burned inside, and the shutters were drawn on the upstairs and downstairs windows.

Hendricksen paused by the front door. He could see no bell. Knocking seemed mildly foolish, but less foolish than breaking in, which he hoped to avoid. He knocked twice, but received no reply. Option Two it was, then.

This stretch of the Herengracht was quiet, even for a Sunday evening in early winter. The sensible approach would have been to inform mutual friends in the Korps that some concerns had arisen for the well-being of Mijnheer De Jaager and his family, but this would have necessitated revealing the location of the safe house. Should De Jaager have decided to take a break in the country or in another European city, perhaps with Paulus and Anouk in tow, he would be most unhappy to return and find the location and nature of this redoubt were now familiar to the authorities. In such an eventuality, Hendricksen’s already fraught relations with the old fixer would likely suffer a terminal decline.

Hendricksen’s eye was caught by a mark on the otherwise pristine paintwork of the doorframe. He used his pocket Maglite to reveal it: a dark oval against the cream, fading to nothing, like a red flare passing over snow. It looked, to Hendricksen, very much like blood. Someone, it seemed, had been careless.

He checked the area one last time for police and found no trace of them. Across the canal, a man and woman were walking arm in arm. From the opposite direction, a small group of young people emerged from a basement bar. Hendricksen waited in the shadows until all had gone their separate ways before reaching into his pack and removing a snap gun and tension wrench. Picking locks was a craft, one that Hendricksen had never had the urge or patience to master. A snap gun did the job faster, although it was much noisier than a lockpick and tended to permanently damage the mechanism, which meant it was useless if one wished to enter someone else’s property without leaving proof of intrusion. But then Hendricksen was also carrying a concealed Glock, and so would have larger problems to occupy him if confronted by men and women in uniform.