Colbeck took another sip of his drink then told his friend about the conversation with Nigel Buckmaster. Stockdale listened intently. He was amused by what the actor had told him about identifying the dead body.

'So he didn't flinch, did he?' he said. 'Mr Buckmaster took one look at the body, nodded his head to signal that it was indeed Mr Kellow then rushed off to be sick somewhere. He'd never make a policeman.'

'Murder victims are never pretty.'

'The ones hauled out of the River Taff are the worst. If they've been in there long enough, they're bloated. I doubt if Mr Buckmaster would even dare to look at such horrors.'

'The most useful thing he told me was that Mr Voke and his son had parted company.'

'It sounds to me as if the son needs more than a passing glance,' said Stockdale. 'There must have been bad blood between him and Hugh Kellow. That gives us a motive.'

'We'll certainly bear him in mind,' agreed Colbeck, 'though, in my experience, obvious suspects are often proved innocent.'

Stockdale guffawed. 'Not if they live in Butetown!'

'What did you find out, Superintendent?'

'Well, at least I discovered what was stolen,' said the other, taking out the sketch and handing it over. 'Mr Tomkins showed me this.'

Colbeck unfolded the paper. 'It's a locomotive based on the Great Western Railway's Firefly class,' he said after only a glance. 'It was designed by Daniel Gooch in 1840 and has proved a reliable workhorse. There are, however, some modifications. In some respects, it's been simplified but there are also refinements that never existed on the original engine – that crown on the smokestack, for example.'

'You seem very well-informed, Inspector.'

'I've always loved trains.'

'I thought I'd show this to every pawnbroker and silversmith in town just in case the killer is tempted to try and sell it.'

Colbeck handed the sketch back. 'I think that's highly unlikely,' he opined. 'How did Mrs Tomkins respond to the news that her coffee pot has gone astray?'