Leeming was puzzled. 'Why didn't the train from which the body was thrown stop at the viaduct? We did. Inspector Colbeck wanted to take a look at the scene of the crime.'

'This morning's train was an express that does not stop at all the intermediate stations.'

'The killer would have chosen it for that reason,' said Colbeck.

'Once he had jettisoned his victim, he wanted to get away from there as swiftly as possible.' He pondered. 'So far, it would appear, we have three witnesses, all of whom were in a similar position. Was anyone else there at the time?'

'According to Enoch Triggs, there were two ladies and a boy on the bank but they fled in fear. We have no idea who they were. Oh, yes,' he went on, studying one of the statements, 'and there seems to have been a man there as well but he, too, vanished. The truth is that Enoch Triggs and his son were too busy trying to rescue the body from the water to notice much else.'

'That takes care of those at the scene of the crime. I presume that you have details of where this barge can be reached?'

'Yes, Inspector.'

'Good. What about the other witnesses?'

'There were none,' asserted Heyford.

'A train full of passengers and nobody sees a man being tossed over the side of a viaduct? That's not an everyday event. It's something that people would remember.'

'I'd remember it,' agreed Leeming.

'Well?' said Colbeck. 'Did you make any effort to contact the passengers on that train, Inspector Heyford?'

'How could I?' asked the other, defensively. 'By the time we were made aware of the crime, the passengers had all dispersed throughout the city.'

'Many of them may have intended to return to Manchester. It may well be that some people live there and work here. Did it never occur to you to have someone at the railway station this afternoon to question anyone leaving Liverpool who might have travelled on that train this morning?'