Fabel showed her his Murder Commission ID and told her there was nothing to be alarmed about. Frau Franzka’s countenance suggested it would take a lot more than Fabel’s presence to alarm her. ‘I’m Frau Klee’s boss,’ he explained. ‘She’s been unwell recently and we were a little concerned about her. Have you seen her lately?’

‘Not for a while,’ Frau Franzka replied. ‘I saw her take some luggage down to her car. It was a Wednesday, so exactly two weeks ago today. It looked like she was going away on business. She had a computer bag and a briefcase with her.’

‘Thanks,’ said Fabel. He and Anna went across to Maria’s apartment door. Frau Franzka watched them from her doorway, then shrugged and went back inside. Anna had brought her collection of keys: a wire coat-hanger bent into a circle with a hundred or more keys attached, like some improvised tribal necklace. Fabel remembered that in the days before central locking and keyless remotes, every uniformed station had the same arrangement for car keys. He decided not to ask Anna why she felt it necessary to have such comprehensive means of illegal entry; he had always suspected that Anna bent the rules a little too far at times. Until today, he had pretended to be unaware of her key collection. After about five minutes and countless keys, they were rewarded by a click. Anna paused and looked over her shoulder at her boss.

‘Does Maria have an alarm system?’

‘I don’t know …’ Fabel looked uncertain for a moment, then nodded decisively.

Anna shrugged and pushed open the door. There was a loud electronic beeping from the alarm keypad inside in the hall.

‘Bollocks …’ she said. Fabel brushed past her and typed in a sequence of numbers. The display flashed ERROR CODE and continued to beep. He hit the clear button and typed in a new sequence. The beeping stopped.

‘Her date of birth?’ Anna sighed.

‘The date she joined the Polizei Hamburg. I checked both in her file.’

‘What would you have done if neither had worked?’

‘Arrested you for housebreaking,’ said Fabel and headed along the hall.

‘You probably would …’

They stood in the living room of Maria’s flat. It was, exactly as they had expected, pristine, ordered and furnished with immaculate taste. The walls were painted white but were hung with brightly colourful paintings. Oils, and originals. He guessed they would be by up-and-coming artists on the cusp of saleability. Maria was the kind of person to temper her art appreciation with acumen.

‘I always envied Maria, you know,’ said Anna.

‘In what way?’

‘Wanted to be like her. You know … Elegant, cool, together.’

‘She’s not together now.’

‘Do you never feel that way?’ Anna asked Fabel as she examined Maria’s CD collection. ‘You know, wish that you could be someone else? Even for a little while?’