'Of course. Look, Dr Haggard, I wonder if it would be possible to see part of that film again. It'll help me explain what I'm doing here.'

Haggard finished his drink, then nodded.

'Why not? I'm intrigued. You could always gatecrash again, of course, but I suppose that might compromise your reputation. Besides, we only have that film until the weekend, so let's see what we can do.'

Downstairs again, Haggard left Pascoe in the viewing room and disappeared for a few moments, returning with a small triangular-faced man with large hairy-knuckled hands, one of which was wrapped round a pint tankard.

'Maurice, this is Inspector Pascoe. Maurice Arany, my partner and also, thank God, my projectionist. I am mechanically illiterate.'

They shook hands. It would have been easy, thought Pascoe, to develop it into a test of strength, but such games were not yet necessary.

As well as he could he described the sequence he wished to see, and Arany went out. Haggard switched off the lights and they sat together in the darkness till the screen lit up. Arany hit the spot with great precision and Pascoe let it run until the entry of the vengeful husband.

'That's fine,' he said and Haggard interposed his arm into the beam of light and the picture flickered and died.

'Well, Inspector?' said Haggard after he had switched on the lights.

'My informant reckons that was for real,’ said Pascoe diffidently.

'All of it?' said Haggard.

'The punch that knocks the girl down.'

'How extraordinary. Shall we look again? Maurice!'

They sat through the sequence once more.

'It's quite effective, though I've seen better,' said Haggard. 'But on what grounds would you claim it was real, if by real you mean that some unfortunate girl really did get punched?'