Dee knew a bit about her, but not everything. Not the personal stuff, the woman stuff. Or about Vasily. She’d never shared her past with anybody. What did John know? How had he found out?

He looked around him, left, right. ‘Let’s go somewhere quiet,’ he said. ‘We have to talk.’

‘Nobody can hear us.’

‘We could be seen.’ He paused. ‘Could we go to my rooms? Everywhere else will be shut. Could you bear it?’

She picked up on his fear now, this lurking unseen presence in the peace of Soho Square on a late summer’s afternoon where the insects buzzed and the pigeons wooed and the sparrows flitted from tree to tree. There was her own fear now, that tumbril of anxiety that she’d had the night Lieselotte had left and not returned. This man linked the two. Because although his description of Lieselotte could match anyone in Berlin, and goodness knows Lieselotte was a common enough name, Betty had no doubt that he was talking about her sister.

Did he know that?

Lieselotte had been pregnant. Did he know that, too? She clasped her hands over her stomach. She should tell him she was expecting his baby. She needed help, and it wasn’t fair that she should shoulder this alone. But he’d rejected her once. She wasn’t sure she could take it twice.

‘All right,’ she said. She followed him out of the square and walked beside him in silence, the ten minutes it took to reach Bury Place and his rooms.

He made a pot of tea, pulled out some malt bread from the pantry, slathered it with butter which had turned a little rancid. Betty scraped it off. They sat at his table, on opposite sides. Behind him was the clock, marking time, soundless. An eight-day clock with its neat, modern mechanism tucked away at the back, its smoked glass face and elegant numerals.

‘Who are you?’ she said.

‘You know who I am,’ he said.

‘I’m not sure I do,’ she said. ‘How did you know I was German?’ She wondered if he was some kind of spy, except that would be too absurd. What on earth would he want to spy on her for? Besides, he was a teacher, for heaven’s sake.

He lifted his cup, put it back crooked on his saucer so it rocked. He settled it, long fingers round its rim. He’s playing for time, she thought.

‘I can’t tell you that now,’ he said. ‘It involves someone I met in Berlin, from those days.’

‘You’ve just lured me here,’ she said. ‘You’re not going to give me anything, are you?’

‘I’ll give you what I can.’

She pushed her chair back, walked over to the shelf, picked up the clock and put it down on the table. ‘Start by telling me how you got this clock. And how you met this Lieselotte.’