The street where she lived was on the outskirts of the city. Here, fingers of countryside clung on to the land with an arthritic grip, a stranded straggle of trees and scrubby grass the only reminders of what used to be there. These last remnants of nature formed divisions between the housing developments, giving their owners an illusion of being country dwellers. They could look out at the darkling woods and imagine themselves lords of all they surveyed, ignoring the fact of their ugly square houses with their two reception rooms, three bedrooms, one and a half bathrooms and a fitted kitchen replicated like some grotesque multiple birth all along the street. He couldn’t see the attraction. He’d rather live in a tiny apartment in the heart of the city than reproduce ugliness along with space. Better still, to be cabined on a boat, a moving world that travelled with you and allowed you to change your view on a daily basis.

He drove slowly along the street, lights on against the gloomy drizzle of the evening, checking the house numbers. There was nothing to distinguish Margarethe Schilling’s home from those of her neighbours. Although the colours of doors and the patterns of curtains varied, somehow they all merged into one amorphous identikit. Her car was parked in front of the garage door, he noticed. He wondered if his own car would be too conspicuous, left on the street when every other vehicle was garaged or on a drive. There was room for the Golf behind her elderly Audi, so he decided to park there.

He walked up to the front door, bag in hand, hoping suburban eyes would be too busy with their own concerns to notice him. Not that they’d remember someone so insignificant. It was only on the inside that he was remarkable. He rang the doorbell and waited. The door opened to reveal a woman of medium height and build. Not too heavy to lift, he thought with satisfaction. Her greying blonde hair was pulled back in a ponytail from a face that looked tired and careworn. Mascara was slightly smudged round her eyes, as if she’d rubbed them without thinking. She wore tailored charcoal slacks and a maroon chenille sweater that effectively disguised her figure. ‘Herr Hochenstein?’ she said.

He inclined his head. ‘Dr Schilling, it’s a pleasure to meet you.’

She stepped back and gestured to him to enter. ‘Straight ahead,’ she said. ‘I hope you don’t mind us talking in the kitchen, but it’s the most comfortable room in the house.’

He’d hoped for her study. But as he walked into the kitchen, he could see it was ideal for his purpose. A scarred pine table stood in the middle of the floor, perfectly positioned for the ceremony that lay ahead. Later, he would find her study and leave his calling card in her files. For now, though, the kitchen would suffice.