Martins was right. I had made a complete fool of myself, but remember that police work in an occupied city is not like police work at home. Everything is unfamiliar: the methods of one’s foreign colleagues, the rules of evidence, even the procedure at inquests. I suppose I had got into the state of mind when one trusts too much to one’s personal judgement. I had been immensely relieved by Lime’s death. I was satisfied with the accident.

I said to Martins, ‘Did you look inside the kiosk or was it locked?’

‘Oh, it wasn’t a newspaper kiosk,’ he said. ‘It was one of those solid iron kiosks you see everywhere plastered with posters.’

‘You’d better show me the place.’

‘But is Anna all right?’

‘The police are watching the flat. They won’t try anything else yet.’

I didn’t want to make a fuss in the neighbourhood with a police car, so we took trams – several trams – changing here and there, and came into the district on foot. I didn’t wear my uniform, and I doubted anyway, after the failure of the attempt on Anna, whether they would risk a watcher. ‘This is the turning,’ Martins said and led me down a side street. We stopped at the kiosk. ‘You see, he passed behind here and simply vanished – into the ground.’

‘That was exactly where he did vanish to,’ I said.

‘How do you mean?’

An ordinary passer-by would never have noticed that the kiosk had a door, and of course it had been dark when the man disappeared. I pulled the door open and showed Martins the little curling iron staircase that disappeared into the ground. He said, ‘Good God, then I didn’t imagine him!’

‘It’s one of the entrances to the main sewer.’

‘And anyone can go down?’

‘Anyone. For some reason the Russians object to these being locked.’

‘How far can one go?’

‘Right across Vienna. People used them in air raids; some of our prisoners hid for two years down there. Deserters have used them – and burglars. If you know your way about you can emerge again almost anywhere in the city through a manhole or a kiosk like this one. The Austrians have to have special police for patrolling these sewers.’ I closed the door of the kiosk again. I said, ‘So that’s how your friend Harry disappeared.’

‘You really believe it was Harry?’

‘The evidence points that way.’

‘Then whom did they bury?’

‘I don’t know yet, but we soon shall, because we are digging him up again. I’ve got a shrewd idea, though, that Koch wasn’t the only inconvenient man they murdered.’

Martins said, ‘It’s a bit of a shock.’

‘Yes.’

‘What are you going to do about it?’