I put a good wide desk between us and gave him a cigarette. I found him sullen but ready to talk, within strict limits. I asked him about Kurtz and he seemed to me to answer satisfactorily. I then asked him about Anna Schmidt and I gathered from his reply that he must have been with her after visiting Colonel Cooler; that filled in one of the missing points. I tried him with Dr Winkler, and he answered readily enough. ‘You’ve been getting around,’ I said, ‘quite a bit. And have you found out anything about your friend?’

‘Oh, yes,’ he said. ‘It was under your nose but you didn’t see it.’

‘What?’

‘That he was murdered.’ That took me by surprise: I had at one time played with the idea of suicide, but I had ruled even that out.

‘Go on,’ I said. He tried to eliminate from his story all mention of Koch, talking about an informant who had seen the accident. This made his story rather confusing, and I couldn’t grasp at first why he attached so much importance to the third man.

‘He didn’t turn up at the inquest, and the others lied to keep him out.’

‘Nor did your man turn up – I don’t see much importance in that. If it was a genuine accident, all the evidence needed was there. Why get the other chap in trouble? Perhaps his wife thought he was out of town; perhaps he was an official absent without leave – people sometimes take unauthorized trips to Vienna from places like Klagenfurt. The delights of the great city, for what they are worth.’

‘There was more to it than that. The little chap who told me about it – they’ve murdered him. You see, they obviously didn’t know what else he had seen.’

‘Now we have it,’ I said. ‘You mean Koch.’

‘Yes.’

‘As far as we know, you were the last person to see him alive.’ I questioned him then, as I’ve written, to find out if he had been followed to Koch’s by somebody who was sharper than my man and had kept out of sight. I said, ‘The Austrian police are anxious to pin this on you. Frau Koch told them how disturbed her husband was by your visit. Who else knew about it?’

‘I told Cooler.’ He said excitedly, ‘Suppose immediately I left he telephoned the story to someone – to the third man. They had to stop Koch’s mouth.’

‘When you told Colonel Cooler about Koch, the man was already dead. That night he got out of bed, hearing someone, and went downstairs –’

‘Well, that rules me out. I was in Sacher’s.’

‘But he went to bed very early. Your visit brought back the migraine. It was soon after nine when he got up. You returned to Sacher’s at nine-thirty. Where were you before that?’

He said gloomily, ‘Wandering round and trying to sort things out.’