'A wife and children are unnecessary handicaps.'

'That's a matter of opinion, Superintendent.'

'Mine is based on experience.'

'Mine is tempered by a recognition of basic human needs,' said Colbeck suavely. 'A police force is not a monastic order, sir. I refuse to believe that celibacy in our ranks is to be encouraged.'

'I'm well aware of your eccentric views, Inspector,' said Tallis with exasperation, 'and I'd be grateful if you kept them to yourself. What time is your train?'

'In just under an hour.'

'Then find Sergeant Leeming and get over to Euston Station.'

'At once, sir.'

'And don't presume to rest on your laurels.'

'I'd never dare to do that.'

'This is an entirely new case.'

Colbeck knew what he meant. It was not the first time that the inspector had answered the call of the London and North West Railway. When a mail train was robbed on its way to Birmingham, a succession of other serious crimes had been committed in its wake. Because of the way he had brought the investigation to a satisfactory conclusion, Robert Colbeck had earned the gratitude of the LNWR as well as that of the Post Office and the Royal Mint. Newspapers had unanimously christened him the Railway Detective. It was an honour that he cherished but it also placed a heavy and often uncomfortable burden of expectation on his shoulders.

'Are you sure you've picked the fastest train?' asked Tallis.

'I couldn't have chosen a better one, sir.'

'What do you mean?'

'The engine driver is a good friend of mine.'

Caleb Andrews was a short, thin, sinewy man of middle years with the energy of someone half his age. Though he had spent his entire working life on the railway, he had lost none of his boyish enthusiasm for his job. Having begun as a cleaner, he had eventually become a fireman before reaching the pinnacle of his profession as an engine driver. Andrews considered himself to be one of the aristocrats of the railway world and expected deference from those in lowlier positions. He was on the footplate of his locomotive, checking that everything was in order for departure, when two familiar figures came along the platform to see him.