He turned as Margarethe followed him, offering a smile. ‘This is very comfortable.’

‘I spend most of my time in here,’ she said, passing him and heading for the stove. ‘Now, would you like a drink? Tea, coffee? Something stronger?’

He measured the distances. The fridge would give him the best chance. ‘A beer would be good,’ he said, knowing this meant she’d have to turn her back on him.

And so it began again. Hands and brain moved in a smooth sequence, following the practised routine without a stutter or stumble. He was bending down to fasten her left ankle to the table leg when the sharp chime of the doorbell made him jerk upright, the cord falling from his startled fingers. His heart thudded in his chest. He felt the choke of panic close his throat. Someone was there, only twenty yards or so away from him. Someone who expected Margarethe Schilling to open the door.

She couldn’t have made an arrangement, he reasoned. She knew he was coming, so she wouldn’t have invited anyone round. It must be someone selling religion or household goods door to door, he told himself, fighting for calm. Either that or one of the neighbours who’d seen Schilling’s car on the drive and expected her to be home. It had to be. Didn’t it?

The doorbell pealed out again, this time for longer. He didn’t know what to do. He stepped away from the table where Margarethe lay spread-eagled, still fully clothed. What if the caller was persistent enough to come round to the back of the house? All it would take would be one glance in the brightly lit kitchen windows. He scrabbled for the light switch. Just as his fingers closed on it, he heard a sound that chilled him even more than the doorbell. The unmistakable click of a key in a lock.

He froze, dry-mouthed, wondering about escape. The front door opened and a man’s voice shouted, ‘Margarethe?’ The door closing, then footsteps heading for the kitchen. ‘It’s me,’ he heard.

Grabbing a heavy cast-iron pan from the stove, he flattened himself against the wall by the door. It opened without a moment’s hesitation and a tall, male shape appeared, crossing the threshold and stopping in his tracks. Enough light spilled in from outside to show the shape of Margarethe’s body lying on the table. ‘Margarethe?’ he said again, reaching for the light switch.

The pan crashed down on the back of his head and the man dropped to his knees like a felled steer. His upper body teetered for a moment then collapsed face down in an untidy heap.