‘When I was having breakfast, in the Station Hotel at Scoone, I found that I had picked up by accident a newspaper that had been tumbled off the berth when the attendant was trying to waken him, and in the Stop Press—the blank space, you know—someone had been pencilling some lines of verse. “The beasts that talk, the streams that stand, the stones that walk, the singing sand—” then two blank lines, and then: “that guard the way to Paradise.”’

‘That was what you advertised about,’ Cullen said, his face growing momentarily blacker. ‘What was it to you that you went to the trouble of advertising about it?’

‘I wanted to know where the lines came from if they were lines from some book. If they were lines in the process of being made into a poem, then I wanted to know what the subject was.’

‘Why? What should you care?’

‘I had no choice in the matter. The thing ran round and round in my head. Do you know anyone called Charles Martin?’

‘No, I don’t. And don’t change the subject.’

‘I’m not changing the subject, oddly enough. Do me the kindness to think of it seriously for a moment. Have you ever, at any time, heard of or known a Charles Martin?’

‘I’ve told you, no! I don’t have to think. And of course you’re changing the subject! What has Charles Martin got to do with this?’

‘According to the police, the man who was found dead in Compartment B Seven was a French mechanic called Charles Martin.’

After a moment Cullen said: ‘Look, Mr Grant, maybe I’m not very bright, but you’re not making sense. What you’re saying is that you saw Bill Kenrick lying dead in a compartment of a train, but he wasn’t Bill Kenrick at all; he was a man called Martin.’