The detective was shaken. 'He would surely not have stolen from his own father?'

'It would not have been the first time, Sergeant. But enough of Stephen,' he said, bitterly. 'I've disowned him. He's no longer welcome here and has no claim on the business. Unlike Hugh, he would never apply himself. That's the secret of the silversmith's trade in one simple word – application.'

'I can't imagine ever disowning either of my children. I love them too dearly. In any case,' said Leeming, earnestly, 'my wife would never allow such a thing to happen. I'm surprised that Mrs Voke was ready to renounce her own child.'

Voke stifled a sob. 'My wife died a couple of years ago,' he said. 'While she was alive, Stephen was far less trouble. Alice knew how to handle him. Once she had gone, he became surly and disobedient.'

'When did you and he come to the parting of the ways?'

'It must have been two or three months ago.'

'Would you have started work on that coffee pot by then?'

'Oh, yes,' replied Voke, 'that was a bone of contention. Because my eyesight is fading a little, I needed someone else to do the more intricate work on that locomotive. Stephen expected that I'd turn to him but Hugh was always my first choice.'

'So your son was aware of the details of the commission?'

'Naturally – why do you ask?'

'Someone lay in wait for Mr Kellow,' said Leeming, 'so they must have known that he was carrying something of great value. Apart from your son, can you suggest anyone else who might have known what your assistant's movements would be?'

'No,' said Voke, 'I would never disclose such details. Hugh has delivered expensive items before without mishap, largely, I suspect, because nobody realised what he was carrying.'

'Could Mr Kellow have confided to anybody that he was going to Cardiff today?'

'I warned him against doing so, Sergeant. Besides, in whom could he confide? He had few friends and he never talked to his sister about his work here.'