Andrea shrugged. ‘When the first one arrived, not long after the attack, I was terrified. But I was still her then. Soft, timid, pliant. Too scared to do anything. Then I decided to change my name and the rest all fell into place. Then the other letters arrived. Even after I’d changed my name and moved apartments. They don’t come often. But they did come.’

‘Have you kept them?’ asked Scholz.

Andrea shook her head. ‘I burn them now without reading them. But the ones I did read were all the same. Mad ravings. How much he wanted to do it again, how he was biding his time.’

‘And this doesn’t bother you?’ asked Tansu incredulously.

‘No. He’s lost his power to frighten me. Maybe we will meet again, but he’s the one who should be afraid.’

‘I need you to think hard about what was in those letters, Andrea,’ said Fabel firmly. ‘I need you to take the time to write down everything you can remember. Do it tonight and we’ll send someone to pick it up from the café tomorrow. Like I said, anything that might give us a handle on his identity.’

‘What about his name?’

It took a moment for Fabel to realise that Andrea was being serious. ‘He signs them?’

‘Every one. The name he uses is Peter Stumpf.’

Fabel heard Scholz groan. ‘Does the name Peter Stumpf mean anything to you?’ Fabel asked Andrea.

‘Nothing.’

‘It obviously does to you,’ he said to Scholz.

‘It sure does. But we’ll talk about that later.’

As they walked back towards Scholz’s car, someone on the other side of the street caught Scholz’s attention.

‘Hi, Ansgar!’ Scholz called over. Fabel and Tansu followed him across the street.

‘Remember the restaurant I took you to – the Speisekammer?’ Scholz said to Fabel. ‘This is Ansgar Hoeffer, the chef. The best in Cologne if you ask me and that’s saying something. How are you, Ansgar?’

‘I’m fine … you?’ Ansgar answered. He was a tallish man with a high-domed head. His sparse hair had been trimmed bristle-short. His eyes seemed large and doleful behind his glasses. But what struck Fabel most about him was that he looked decidedly uncomfortable.

‘The best,’ said Scholz. ‘What are you doing in this part of town?’

Ansgar again looked flustered for a moment. ‘Oh, I had a few things to do. How was your meal the other night?’ Ansgar addressed his question to Fabel.

‘Oh, I’m sorry, I meant to introduce you …’ said Scholz. ‘Ansgar, this is Principal Chief Commissar Fabel of the Hamburg Police. He’s down here … on a course.’

Fabel and Ansgar shook hands. ‘It was excellent,’ said Fabel. ‘We both had the lamb ragout. Delicious.’

After a brief exchange of more small talk they went their separate ways, Ansgar walking off towards the city centre with a purposeful stride.

‘Great cook,’ said Scholz as they reached his car.