Fry saw from the DI’s expression that he was starting to lose faith in his expert. Dr Kane seemed to be setting up more obstacles than she was helping to overcome. But experts loved to make things look more complex than they really were, didn’t they? It helped to justify their fees.

‘So what about the dead place?’ said Fry. ‘And the gibbet? The flesh eater?’

But the psychologist had begun to gather her papers together. ‘That’s your job, I believe. You have an individual here who’s trying to draw attention to himself, perhaps because he knows subconsciously that he needs help. Right now, he’s doing his best to assist you. His clues are a little obscure and ambiguous, certainly. That’s because he has to appear to be demonstrating his superior intelligence. But if you listen properly to what he’s telling you, I’m sure it will help you far more than I can at this stage.’

Dr Kane stood up ready to leave, then paused. She was looking at Fry, not at Hitchens, when she delivered her parting advice.

‘It’s generally true,’ she said, ‘that you can learn a lot by listening to what other people have to say.’

The regional manager for PNL Parking was called Hicks. Cooper found him in a cramped office on the street level with an attendant in a yellow fluorescent jacket.

‘We’re bound by all the rules, you know,’ said Hicks. ‘We have to register the CCTV system and make sure we’re compliant with the Data Protection Act.’

‘No one is suggesting you’ve broken any rules,’ said Ben Cooper for the third time.

But Hicks barely blinked. ‘Apart from anything else, footage won’t be accepted as evidence in court if we don’t comply with the rules,’ he said. ‘And registering the system means we have to deal with requests from people for copies of film.’

‘Do you get many requests?’

‘Some. A lot of them are too vague, though. They have to give us an idea of what time they might have been filmed, where they were and what they look like.’ He shrugged. ‘Most of them give up when they’re asked for details. They’re just fishing. And then there are some where we have to admit we didn’t film them at all, because the camera they saw was a dummy. Well, we don’t say dummy. We just say the camera wasn’t functioning at the time.’

‘And the camera on Level 8 would be one of those dummies?’ asked Cooper.

‘Yes.’

‘Has it always been non-functioning?’

‘For as long as I can recall.’ Hicks hesitated. ‘Yes, I’m pretty sure it was installed like that. It’s a bit ridiculous really, but at the time it was considered more economical. Cameras were supposed to be a deterrent, as much as anything else.’

‘I’d like to see any requests you have on file for copies of film from the camera on Level 8.’

‘As I said, we don’t give out copies of film from that camera, because it’s non-functioning.’