'Are you the detective from London?'

'Yes, Mr Hooper. I am Inspector Colbeck.'

'I thought you didn't come from around here,' said Hooper, looking him up and down. 'Liverpool is a philistine place. It has no real appreciation of art and architecture. It idolises conformity. Those of us who cut a dash with our clothing or our way of life could never fit easily into Liverpool. I hate towns of any kind myself. I choose to live in the country and breathe in free air.'

Ambrose Hooper was wearing his crumpled white jacket over a flowery waistcoat and a pair of baggy blue trousers. A fading blue cravat was at his neck. His straw hat lay on the table beside a dog-eared portfolio. Some paint had lodged in his beard. Wisps of grey hair stood up mutinously all over his head. Colbeck could see that he was a man of independent mind.

'I'm told that you believe I am wrong,' said Colbeck.

'I don't believe it, sir – I know it.'

'How?'

'I was there, Inspector.'

'At the Sankey Viaduct?'

'Yes, I saw exactly what happened.'

'Then why didn't you give a statement to the police?'

'Because that would have meant waiting an age until they arrived on the scene,' explained Hooper. 'Besides, there was nothing that I could do. The body was hauled aboard that barge. I felt that it was important to record the event while it was still fresh in my mind.'

Colbeck was delighted. 'You mean that you went home and wrote down an account of all that you'd seen?'

'I'm no wordsmith, sir. Language has such severe limitations. Art, on the other hand, does not. It has an immediacy that no author could match.' He picked up the portfolio. 'Do you want to know what I saw at the Sankey Viaduct yesterday?'

'Very much so, Mr Hooper.'

'Then behold, my friend.'

Untying the ribbon, the artist opened the cover of the portfolio with a flourish to reveal his work. Colbeck was flabbergasted. An unexpected bounty had just fallen into his lap. What he was looking at was nothing less than a detailed photograph of what had actually happened. Having read the statements from the three witnesses on the barge, Colbeck had built up a clear picture of the situation in his mind's eye. Hooper's work enlarged and enlivened that mental image.