As they moved towards the door, Sir Alan put his hand on Kate’s shoulder to stop her. ‘One moment,’ he said. The others hesitated, but he gestured at them to continue. ‘I’ll see you in the office in the morning,’ he told them, ‘and very well done. For all the issues, we got what we went to Berlin for and that is a feather in all of your caps.’ That seemed intended more for Suzy than the rest of them and she smiled for the first time since they had left Berlin.

He waited until the door was closed, then sat on the bed.

‘Are you all right, sir? As I said, I’m very happy to—’

‘I’m as all right as you are,’ he said, ‘which is not very bloody okay at all. But neither of us has any choice but to plough on, do we? Anyway, that’s not why I asked you to stay behind. We may have a problem with the foreign secretary.’

‘In what way?’

‘She’s getting cold feet.’

‘Why?’ Kate couldn’t quite believe this.

‘Because it’s a very big call and she simply isn’t used to making them. She’s about to authorize an operation to oversee a major defection – which, for all that we’re recommending it, is still a significant step for someone new to this kind of decision-making. The controversy it will bring with it would likely test the bravest of politicians and Meg Simpson is not one of them.’

‘You think she’ll refuse to send the letter?’

‘I don’t know. But all I am saying is that it’s not a given she’ll agree to this tomorrow and we may have to work hard to persuade her.’ He stood again. ‘I’d better go back to Alice. Get some sleep, Kate. You look like you need it.’

By the time Kate passed the room further down the corridor, Sir Alan was seated at his wife’s bedside again, head bent as he read to her. Kate watched him for a moment, envious of his devotion and loyalty. It made her feel lonelier still.

She walked home, despite the rain, which had slowed to a drizzle. She found herself wishing Sir Alan had not left her with that departing instruction about sleep, which loomed larger with every step she took homewards. She recalled the days when the house in Battersea had represented only comfort, love and rest. Now it served as the instrument of her torture, and that alone made her feel guilty. What kind of mother doesn’t want to return home to her children?