Ketty said: ‘We’ll give it a couple of minutes to cool off. We normally do not allow the public in here unaccompanied. The door is still a problem for us. We have a concealed override outside, which only I and my partner, plus a few members of the staff, know how to use. Willer left explicit instructions that there must be none inside. Although this is not the original door, which at one point was damaged, it was rebuilt exactly to Willer’s own design. But the door itself is separate from the switching. Willer devised a clever system – when he was inside the building he had secret switches for both opening and locking the door. Two of them were concealed on the stage, and we found and removed them when the stage was taken down. But we know there are others because Willer’s instructions warned against touching them – we’ve never been able to locate them. Obviously, if the public has access we can’t take any risks, which is why we have the override. The visitors can handle and manipulate the illusions on display, but we always warn them never to touch anything else. The other switches must be somewhere inside – the kids love knowing that, and they run around putting their hands on everything they see.’

‘Do they ever find them?’

‘Not yet. We ransacked the place when we remodelled. This was a secret system designed by Willer. He knew exactly how to hide something like that.’

‘Did Mr Willer lock the door on the day he was murdered?’

Ketty looked sharply at Spoder. ‘Why do you say he was murdered?’

Spoder held up the file. ‘I’m a former police officer, ma’am. Some of my colleagues investigated Willer’s death.’

‘Does this mean the police are re-opening the case?’ Ketty said. ‘We should have been warned. We’re running a business here.’

‘It’s nothing like that,’ I said quickly. ‘We’re just here out of interest. I wanted to see the place where it happened.’

‘Willer died a decade ago. It’s in the past, forgotten. Few people have ever heard about what happened. We don’t want to lose business. Most of the people who come here are families.’

‘On the other hand, you might get an extra boost,’ Spoder said. ‘Kids love macabre scenes. Mine certainly did.’ This came as a startling surprise. I had no idea Spoder had children. How little we sometimes know of the people we work with! While I was still digesting this thought, he went on: ‘We have a professional interest in this. My companion here is Todd Fremde, the novelist, the thriller writer. You possibly know his books? I retired from the police years ago, as I told you.’

‘Then what’s that file you’re holding?’ Ketty said. ‘Is it something connected with the police? Is it for a book?’