‘I fully understand that, Charles. Please come here.’ I was firmer with him than I had been before.

‘Very well.’

‘You put him in his place,’ Tibbot said, as I returned to the parlour.

‘Yes, I suppose so. He can be very difficult.’

‘How do you mean?’

‘Oh, nothing much. He’s just very off-hand. Nick says it’s because Charles went to Harrow and resents having to take orders from a grammar-school boy, let alone from me.’

‘I’m sure that’s quite the comedown in his world.’

After twenty minutes, Charles stood in the hallway, brushing down his jacket and muttering about the cost of having come by cab. Tibbot was waiting out of sight upstairs. On the way to the parlour, Charles tripped over the paraffin lamp that Nick used when the smog was heavy or when the electricity to the house cut out, refilling it from one of the nearby bottles of oil that also went into our heaters. He swore in annoyance.

‘Do you remember this photograph being taken?’ I asked when we had sat down.

He glanced at it. ‘No.’

‘You weren’t the one holding the camera?’

‘No, I don’t believe so.’

‘What about this woman?’ I said, pointing to the driver of the car.

‘No idea. A friend of your husband, I presume. And his wife.’

‘You’re positive you don’t know?’

He took out one of those foul Soviet cigarettes, tapped it on the packet and lighted it. ‘Yes.’

‘Do you know when it was taken?’

Charles looked at it again briefly and shrugged. ‘Pre-War?’

‘Pre-War? Nick doesn’t look that young. A few years younger, perhaps. And, look, there’s bomb damage to the street.’

‘If you know yourself, why are you asking me?’

‘Charles,’ I soothed my own voice. ‘Nick is in trouble. I think we can help him. But I need to know who this woman is.’

‘I haven’t the faintest idea.’ He shifted in his seat. ‘But, Mrs Cawson, one thing I do know is that if you do anything that the Secs don’t like, such as poking around or talking to people about his arrest, it won’t go in Dr Cawson’s favour. Or in anybody else’s. If Dr Cawson has done nothing wrong, as I am sure is the case, he will soon be released and we can go back to how things were. It’s not worth the risk.’