‘Otto, I need a name for this customer. Or at least a description.’

‘That’s easy. I don’t think I have an address or anything: he’s never actually ordered a title. I can look back and see if I can get a credit-card slip or something. But, like I say, remembering the name is easy. He spoke perfect German with only the slightest hint of an accent, but he had a British or American name: John MacSwain.’

Friday 13 June, 3.45 p.m. Rotherbaum, Hamburg.

He had, at least, had the courtesy to inform Kolski at LKA7 Abteilung Organisierte Kriminalität of his intention. Fabel could tell that Kolski was not happy about it, but information had not exactly been flowing from the Organised Crime Division and as a result he felt entitled to pursue his inquiry across boundaries.

Fabel was aware that he was looking at three million euros’ worth of property. Mehmet Yilmaz’s three-storey Rotherbaum house was, ironically, only ten minutes’ walk from Fabel’s flat. Its Jugendstil Art Nouveau façade presented a convinced elegance to the tree-lined street. It was one of a row of five houses, each equally vast in scale, each equally solid in presence, each totally different in style: Bauhaus sat next to Art Deco next to Neo-Gothic.

Fabel had expected the door to be answered by a broom-moustached Turkish heavy. It wasn’t: an attractive young housekeeper with short but lustrous golden blonde hair politely asked who was calling and for whom, and guided Fabel through a hallway of polished stone to a large round reception room. This was the centre of the house; the room was the full height of the house and capped with a cupola whose central, circular, stained-glass skylight dappled the floor with splashes of colour. From some far corner of the house Fabel could hear halting piano-playing and the sound of children laughing.

There were a couple of piles of leather-bound books on the vast circular walnut table that sat in the centre of the reception room. Fabel had just picked one up, a second edition of Goethe’s The Sorrows of Young Werther, when a tall, slim and clean shaven man of about fifty entered. His hair was mid-brown and greying at the temples.

‘We spoke on the phone, Herr Kriminalhauptkommissar. You wanted to speak to me?’ asked Mehmet Yilmaz, without a hint of a Turkish accent.

Fabel became aware that he was still holding the Goethe in his hand. ‘Oh, I’m sorry …’ He put the book down. ‘Wonderful condition. Do you collect?’

‘As a matter of fact I do,’ answered Yilmaz. ‘German romantics, Sturm und Drang, that kind of thing. Whenever I can – whenever I can afford – I like to pick up first editions.’

Fabel suppressed a smile: in these surroundings it was difficult to imagine Yilmaz struggling to pay for anything. The Turk walked over to the table and picked up another, smaller volume in a rich burgundy binding.

‘Theodor Storm, Der Schimmelreiter – a first edition and my latest acquisition.’ He handed the book to Fabel. The burgundy leather was soft and yielding. Almost warm. It was as if its age were palpable: as if Fabel’s fingertips were brushing against all the other fingertips that had handled the book over the past century.