'It was a tank engine that exploded,' explained Colbeck, 'and it had run over 90,000 miles without a problem. When it was built, however, its boiler plates were thinner than has now become standard. Over the years, they'd been patched up. Under extreme pressure, they finally gave way.'

'What a horrible death!'

'It's a risk that railwaymen have to take, Victor. Boilers burst far more often in the early days of steam transport. There have been vast improvements since then.'

'I've never known a horse blow up,' said Leeming, pointedly.

'Perhaps not but they have been known to bolt before now and overturn cabs or carts. Also, of course,' Colbeck reminded him, 'even the largest coach can only carry a limited number of passengers. When the London to Brighton line first opened, four trains pulled a string of carriages containing 2000 people – and they arrived at their destination without any mishap.'

'What do you think happened in this case, Inspector?'

'It's too early to speculate.'

'The telegraph said that two trains had collided head-on.'

'One of them, fortunately, was carrying no passengers.'

'We're going to find the most terrible mess when we get there.'

'Yes,' said Colbeck, looking up at the sky. 'And the light is fading fast. That will hamper rescue efforts.'

'What exactly are we looking for?'

'What we always look for, Victor – the truth.'

It was like the aftermath of a battle. Mangled iron and shattered wood were spread over a wide area. Bodies seemed to be littered everywhere. Some were being lifted onto stretchers while others were being examined then treated on the spot. Dozens of people were using shovels and bare hands as they tried to clear the wreckage from the parallel tracks. The listless air of the wounded was offset by the frenetic activity of the railway employees. Carts were waiting to carry more of the injured away.