‘What operation?’

‘It should prove who has been betraying us.’ She looked across at him, trying to decipher the strange look on his face. Was it consternation, fear or regret?

He turned to the window. ‘Are we going to make it?’ he asked.

‘I don’t know.’

He wiped the condensation from the glass. ‘What do you mean? Who’s been betraying us?’

Kate wondered why that had not been his first question. ‘We have an agent at the top of SIS who’s been working with the Russians for years. It was almost certainly his idea to recruit you as a decoy.’

‘Who?’

‘We’ve narrowed the search down to Sir Alan or Ian Granger.’

‘Christ,’ Stuart muttered. ‘And whoever it is knows you’re here?’

‘If they didn’t before, they will now.’

Stuart was staring at his hands, turning them palm down, then up again, as though he was about to strangle her and contemplating whether he had the strength, physical or otherwise, to do it. ‘What went wrong with the operation?’ he asked eventually.

‘They closed in on our source after he made the transfer.’

‘So you have the material?’

‘Yes.’

‘What happened to the source?’

‘I don’t know.’

She waited, more absorbed now in the danger he might represent than in who could be tailing her. Long gone was the regretful, remorseful, loving Stuart of her recent acquaintance and fond memory.

‘What happened to your back-up?’

‘She disappeared.’

Kate took it as a good sign that he didn’t enquire who it was. Perhaps he just assumed she had come with Julie.

Stuart settled back into a brooding silence. It was half an hour before he spoke again. ‘We’ll never get out of Russia,’ he said.

‘We might.’

‘We’re both destined to die here, leaving our children as orphans.’ He looked at her. ‘And I’d love to claim it was your fault, but we both know who is to blame.’

Relief flooded her. Not for the first time, she had mistaken self-loathing for some kind of looming threat. ‘I think you have to accept,’ she said, ‘that we’re both pawns in this game. And that it was devised long ago by someone who has been able to out-think us at every turn.’

‘When you work out which one of those bastards it was,’ he said, ‘I hope you chop them into a thousand tiny pieces.’ He shook his head. ‘I never liked either of them – a snob and a social climber.’ He looked at her. ‘They’ll catch up with us. We have to face that fact.’

‘Maybe,’ she said.

‘You think we can outwit them?’ He was smiling at her again.

‘Maybe.’ She smiled back.

‘You look wired for bloody sound,’ he said. ‘So let me know when you want to relax enough to let me drive.’

After that, the day closed in with a steady gloom that Russia seemed to have made all its own. Fog alternated with sleeting rain. Visibility was negligible and Kate used the unexpected cover of the weather to turn off the main road, wait a while and come back on to it again. But she wouldn’t give up the wheel.