'I'm really only interested in the main bar, foyer and out front,' Rebus said.

'I could edit them down to another tape, but we'd lose definition. The recording's duff enough as it is.' The technician scratched inside the sagging armpit of his black T-shirt.

Rebus leant forward a little, pointing at the screen. 'Coming up now.' They waited. The view jumped from back alley to dance floor. 'Any second.' Another cut: main bar, punters queuing three deep. The technician didn't need to be told, and froze the picture. It wasn't so much black and white as sepia, the colour of dead photographs. Interior light, the audio-visual wizard had explained. He was adjusting the tracking now, and moving the action along one frame at a time. Rebus moved in on the screen, bending so one knee rested on the floor. His finger was touching a face. He took out the assortment of photos from his pocket and held them against the screen.

'It's him,' he said. 'I was pretty sure before. You can't go in a bit closer?'

'For now, this is as good as it gets. I can work on it later, stick it on the computer. The problem is the source material, to wit: one shitty security video.'

Rebus sat back on his chair. 'All right,' he said. 'Let's run forward at half-speed.'

The camera stayed with the main bar for another fifteen seconds, then switched to the second bar and all points on the compass. When it returned to the main bar, the crush of drinkers seemed not to have moved. Unbidden, the technician froze the tape again.

'He's not there,' Rebus said. Again he approached the screen, touched it with his finger. 'He should be there.'

'Next to the sex goddess.' The technician belched again.

Yes. Spun silver hair, almost like a cloud of candyfloss, dark eyes and lips. While those around her were intent either on catching the eyes of the bar staff or on the dance floor, she was looking off to one side. There were no shoulders to her dress.