‘That was quick.’ Kate spun round to see her former boss silhouetted in the doorway. ‘You’re thinking I shouldn’t have smuggled top-secret files from the office and you’re dead right.’ He stooped to kiss her. His hands were covered with grease.

‘I meant to tell you this morning, you look well,’ she said.

‘I do not!’ He gestured at the deep leather sofas in front of the fireplace. ‘Take a seat. I just need to get this crap off my hands.’

Kate slipped into the armchair closest to the window and listened to the soothing gurgle of the water outside. She surveyed the collection of military history books arranged on the shelf and recalled how thrilling it had been to be here on their first weekend visit as a family, the sense that somehow, seated here with a whisky by the fire late at night, she had been admitted into an important inner sanctum.

Mrs Evans came with coffee and chocolate biscuits. ‘Don’t let him eat too many,’ she said. ‘I had to let out his trousers last week.’ She smiled at Kate again. ‘You look very well, Mrs Henderson. I asked about the children, but how is that charming husband of yours?’

Clearly, Sir Alan was not in the habit of gossiping about major developments at work to his housekeeper, which was perhaps encouraging, Kate thought. ‘He’s fine also, thank you.’

Sir Alan came in, still drying his hands. ‘How’s the MG?’ Kate asked.

‘The most infuriating machine ever made. I kept promising Alice that I’d get rid of it.’ He placed the towel on the bookshelf, in front of a series of tomes about the Boer War. He sat opposite Kate. He certainly didn’t look any thicker around the middle, though he lacked the air of suave charm that had once been the toast of Whitehall.

‘I’m sorry,’ she said. ‘It must be so hard being here without her.’

He stared at his hands. ‘It is hard not to think of the retirement we might have had together.’ He shook his head. ‘If I’d known you were coming today,’ he said, ‘I’d have tidied myself up.’

‘You want to explain why you stole all those files from the office?’ she asked, smiling at him.

‘Ah, I took them before I left, so “stole” might be overstating it a touch.’

‘Why did you remove them?’

Sir Alan leant forward to pour himself a cup of coffee. He chose three biscuits, then wasted a few seconds elaborately cleaning his tortoiseshell glasses. They didn’t look much clearer when he put them back on. ‘I was trying to rationalize the overall sense that I had been mugged,’ he said. ‘Which this morning only served to underline. But perhaps that’s what all bitter old men do when they have nothing better to turn their minds to.’

‘You’re neither bitter nor old.’

‘Oh, I wouldn’t be so sure of that – on either count. Betrayal does leave a bitter taste in the mouth.’

She assumed he was talking about Ian, but it was a statement delivered with finality, as if a generalized reflection on the human condition. ‘So what have you concluded?’ she asked. ‘From your studies of the past?’