Peggy thought that this incident was an aberration. She saw me as a sweet little girl whose loneliness and longing for family had put her in danger, though it was Peggy’s own startled screech at seeing me in the tree that almost made me fall out of it. But my spying was no aberration. I simply made sure Peggy never caught me at it again.

Peggy was in the habit of leaving the laundry room window open so she could dangle out the hose that vented the hot air from her tumble dryer. The laundry room was Peggy’s favourite place for private conversations. I could peek from my father’s dusty first-floor study and see right into that laundry room.

I loved my father’s study, where I often hunted for clues about my parents, though I only ever found one thing. A photograph of them on their wedding day, hidden in his copy of A Tale of Two Cities. I liked to sit and read in my father’s old armchair, which was covered in green leather. I’d dragged it near the window. From there, I could monitor what was happening at Peggy’s. If her washing machine and tumble dryer were off, then listening in was no challenge. In fact, I regarded such a circumstance as an invitation.

And that is how I came to hear Peggy and Milly talking together when I was back home in St Ives, two months after my disastrous final MI5 interview. As soon as I saw that the laundry room light was on and Peggy and Milly had gone in, I ran downstairs, slipped into the garden, squeezed through the rip in the fence Milly and I always used as a not-very-secret passage, and flattened myself against a tangle of Peggy’s honeysuckle.

‘She’s so deflated,’ Peggy was saying, ‘since she’s come home. I think she’s embarrassed about the reason – she can’t bear to look your father in the eye.’

I’d had to say something about why MI5 didn’t give me the job, because Peggy and James and Milly knew I’d got to the final stage of the recruitment process. There was no disguising the outcome.

‘She was brave to tell us, Mum,’ Milly said. ‘And fucking stupid.’

‘You don’t need to use that language, Milly.’

But Milly was right. I had been stupid to reveal the truth about the nature of the way I’d messed up. What had possessed me to give them the details? Perhaps I did it because it was the most un-spy-like action I could take, a kind of embracing of my failure. It was an act of self-sabotage I decided never to repeat.

‘Sorry.’ Milly didn’t sound at all sorry. ‘People say all sorts of shit.’

‘Honestly, Milly,’ Peggy said.