‘What? Oh! Yes, what happened. London was thick with snow. I was trying to get home to Chelsea from Marble Arch. All the buses were full. I couldn’t get a taxi. It was dark, freezing hard, snowing, the ducks standing about on the ice. The snow blotted everything out. I walked through the park. Then, as I walked along the Serpentine towards Knightsbridge barracks, there she was. We were nose to nose in the snow. She laughed when she saw me. Her face lit up with pleasure. “My Tom’s little wifey,” she said. “Does he let you out alone?”’

Matilda laid her knife and fork side by side and looked across at Hugh. ‘It annoyed me.’

‘So?’ He studied her face while she paused.

‘So I hit her.’ Matilda was now back there, standing in the snow by the Serpentine. ‘I hit her as hard as I could. She was taller than me. She slipped down the edge onto the ice, tried to get her balance, slid on out, then, crack, she went through, disappeared.’

‘What did you do?’

‘I waited for her to pop up but she didn’t. I suppose she went sideways under the ice. I ran all the way to John’s house. He lived off Sloane Street in those days. He was in when I banged on the door. I told him what I’d done. He’d just got in, he was shaking the snow off his bowler and swishing his umbrella. I remember that clearly. He’s a fussy old bachelor, wants me to call him Piers now. It suits him, his new job. He’s hoping to get a knighthood. Sir Piers would be grander than Sir John. I tease him.’

‘What did he do?’ Hugh suppressed a longing to kick her shins.

‘Oh. He made me sit down, gave me a stiff brandy, listened to what happened, then said I was not to tell Tom, ever. He asked me if anyone had seen it happen. I didn’t think so. It was snowing so hard I couldn’t see more than a few yards, in fact I’d hardly seen her fall through the ice, I only really heard it. Well,’ she stood up, ‘that’s all. John took me home to Tom in his car, said he’d overtaken me in the street. Tom was pleased to see me. I cooked dinner. It was steak, I remember that, black market. It was delicious.’

Hugh allowed the pause to lengthen.

‘I suppose the snow covered your footprints.’

‘I suppose it did.’

‘When was she found?’

‘When it thawed, weeks later. Tom read it in the paper at breakfast. He said, “Oh look, old Duplex is dead. Found drowned in the Serpentine.” Old Duplex was her pet name, her real name was Felicity.’

‘What did you say?’