Cooper put his head round the door, and Fry hastily slid the postcard under the papers on her desk.

‘I’m sorry to tell you this, Diane,’ he said, ‘but I phoned the Interior Ministry in Pleven and asked for this colleague of Georgi Kotsev’s. The name he gave you was Hristo Botev, right?’

‘Yes. What did Botev say?’

‘He wasn’t there. He hasn’t been there for quite a long time.’

‘Oh.’ Fry looked at him curiously. ‘He’s retired, perhaps?’

‘You might say that. When I eventually got someone on the phone who spoke English, he made me repeat who I wanted several times, then burst out laughing. In fact, he seemed to be sharing the hilarity round the office.’

‘Did Georgi play a joke on us?’

‘A pretty pointless joke. When he could pull himself together, the officer explained that Hristo Botev was a Bulgarian revolutionary martyr, who died fighting the Turkish Empire in the nineteenth century. It seems Hristo was a cross between Robin Hood and Winston Churchill. They still commemorate his death every year on the second of June. There are several football stadiums named after him.’

‘Football stadiums?’

‘Well, Georgi did say he was very celebrated in Bulgaria. A great hero.’

Fry could hardly bring herself to speak. ‘Yes. Thanks, Ben.’

‘Don’t worry. He was just pulling your leg. It must be the Bulgarian sense of humour. Pity, though – I still want to ask Georgi whether he saw a woman by the river that night.’

‘There was no woman,’ she said automatically.

When Cooper had gone, Fry put the postcard back and finally forced herself to look at the photograph.

The card had hardly been necessary, because the photo told her everything she needed to know. It showed two people standing in front of a wide, circular tower with a flight of steps and an entrance like a very tall letter ‘H’. She wouldn’t have recognized the building, but for the postcard. The Pleven Panorama.

Georgi Kotsev was in full uniform, with his silver badge pinned to his breast pocket. And very smart he looked, too. The blue tunic and epaulettes suited him even better than a black leather jacket. Below the high crown of his service cap, Kotsev was smiling. It was a smile that had become familiar to Fry in the few days that she’d known him. It made her heart turn over until she felt queasy.

But here, the reason for Georgi’s smile seemed to be the woman standing next to him. She was very striking, black-haired and dark-eyed, wearing a blue scarf and a red silk blouse, open at her throat. She was no taller than Georgi’s shoulder, and he had his arm around her waist. She was like a dark rose in his hand.

But that wasn’t all. Not by a long way.