‘Do you believe this?’

‘Wait. There’s more. So far the story is that Henri was let down by an ally. But Nikola’s paranoia goes deeper than that. It is not just that Vernhes did not assist Henri; Nikola claims that he invited the Germans to do the job of wiping him out, if I picked up all his dark hints and suspicions. So after agreeing the rescue plan with Henri, Vernhes tipped off the Germans and retired quietly home with his men, leaving Henri and his men to be massacred.’

‘Can it be true?’

‘It’s hard to say. It’s a well-established tactic to let the enemy destroy your rival. Look what Stalin did outside Warsaw last year. The free Polish underground was wiped out by the Germans, while the Red Army held back on the other bank of the Vistula. It then marched into Poland with its own Polish exiles in tow.’

‘But what for?’ Ariane cried. ‘Why would it be worth doing such a terrible thing?’

‘I wanted to ask you that.’ She spun round, as if he had accused her; then, seeing that he was continuing to speak, she relaxed. ‘You know the characters better than I do.’

‘Vernhes likes power. I would say that is his defining characteristic. Nikola is a far shrewder man than his wild appearance would let you think.’

Theo put his aching head in his hands.

‘What are you going to do about it?’ Ariane asked.

‘Nothing. In such a case, Vernhes’ people would hold a revolutionary court, condemn the victim, execute him out of hand. Look what happened to you. But I can’t do that, and I don’t have the evidence to do it properly. Nikola would never speak.’

The general had been right after all. True justice required more than a jumble of suspicions and guesses, however acute and lucky they might be. He knew, or thought he knew, what had happened to Henri, and that would have to be enough.

‘Nikola also told me that you were used to spy on the Germans while they were based here and to feed them false information. A nasty, dangerous little job. Did they ever suspect you?’

Ariane stood up and walked over to the window. She remained with her back to him, looking out.

‘It was the worst thing I have ever had to do,’ she said passionately. ‘Yes, they suspected me all the time, both the Germans and the Resistance. I got information, I gave information, but neither side trusted it. I didn’t want to do it. From the first, I hated it. I begged not to have to do it. The United Committee of the Resistance, that is, Vernhes, ordered me.’

‘The trouble with feeding the enemy false information,’ Theo said, ‘is that when it is revealed as false they suspect the source. That never happened to you? Then they try to turn it round, create a double agent.’ In contrast to the emotion in her voice, he spoke as if he were discussing an abstract question of an intelligence technique with his students at the Ecole Militaire.