I went over to him and put my arms round him. He felt rather stiff and reluctant at first. ‘Angus – I don’t mind – really. Perhaps I’m supposed to, but I don’t!’

Laughing now, he pulled me into his arms. We stood holding each other more easily, kissing, the house quiet around us.

‘It must look very dark in here from out there,’ Angus said after a while, looking over my shoulder towards the garden. ‘There’s no one out there now. They must have come in.’

A few moments later, hearing the sound of the front door, we sprang apart again. There were brisk footsteps along the hall and Alec Kemp appeared at the door.

‘Hello, you two,’ he said, with that smile he could bring out, mischievous and complicit as if he guessed exactly what we were doing there. ‘Got all you want?’ He stood loosening his tie and removing the studs from his collar. His suit was a loud tweed. ‘Elizabeth upstairs?’

We heard her voice from behind him. ‘Darling, hello. Did you have a good day?’ Her tone was caressing, solicitous, as if addressing a convalescent. ‘Poor thing, having to work when it’s so hot.’

‘Oh, it wasn’t so bad. Where’s Olivia? Upstairs?’

‘I thought she was with you,’ Elizabeth said to Angus and me. Her right hand moved nervously to her throat, fingers nipping a fold of skin. ‘She’ll be around somewhere.’

Ten minutes later, when Angus and I were ready to leave, Alec came down from changing into more casual clothes.

‘I gather that brother of yours is here too,’ he said to me tersely. Every trace of mischief was gone from his voice.

‘He was,’ I told him, bewildered. ‘But he must have gone on home.’

‘Well,’ Alec replied grimly. ‘We’ll see.’

Outside, the only signs of life were two magpies, stalking across the grass.

Alec strode down the lawn, tensed and threatening, his hands clenched. The sight of him filled me with a terrible sense of dread though I could make no sense of it at the time. Angus and I followed.

Our feet were silent on the grass as we approached the gazebo, neat as a doll’s house in the corner of the lawn. We were right behind Alec as he pushed the handle then stood across the doorway. The scene came to me in painful, jumbled images, like a cubist painting. Olivia’s face, hair loosened in thick waves, her expression frozen; long, brown arms, the blue dress startling at her waist, her white, white breasts. And William’s hand, arrested in the act of touching her, looking huge and dark as it was snatched away. I found my eyes moving anxiously downwards to check the extent of my brother’s embarrassment, but he was fully clothed, everything fastened. His face was enough, flushed red like raw meat, eyes childishly wide. He could not speak. The two of them sat like trapped rats.

There were no smiles from Alec this time, no knowing looks. This was his daughter, matured and ripe as a siren, legs spread on the striped couch, pulling the blue cloth up fast now to cover her nakedness.