‘She wasn’t always such a sourpuss,’ explained my aunt, as Mother scudded away on clouds of disapproval. ‘Before the last war,’ she confided, ‘Violet was quite the life and soul of the soirée , singing silly ballads and larking the night away. She knew all the latest dances and taught them to the young men. But then Edwin got killed and she thought she’d never get off the shelf, until they found your poor ruddy father.’

‘Who was Edwin?’

‘Her first fiancé, a Montagu. He went exploring the Hindu Kush and returned to write a rather daring book on puberty and polygamy before getting himself killed in the first wave on the Somme. Violet wore black for two years, never left the house, must have had one of those whadyamacallits, nervous breakdowns. By the time the boys came home, those that did, she was pushing thirty and no poster-girl. I always thought yer dad was a bit of a hero, taking her on, but he never complains, does he? A good bloke, Morty Simmonds, I always say. I knew his family down Mile End. Didn’t have two spare beans for a Sabbath cholent.’

‘Martin, do mingle a bit,’ rasped my mother, returning to Wallflower Corner. ‘Introduce David properly to the rest of our family.’

Dovidl caught my eye and gave a mock-sigh. He was trapped in a circle with Dr Steiner and other émigrés whose efforts to address one another in patriotic English verged on the impenetrable. ‘Excuse me, Dr Steiner,’ I intruded politely, ‘may I take David away for a few moments?’

‘Phew,’ said Dovidl, as we breathed a gust of fresh garden air. ‘As long as you are there to rescue me, I could do this for a living.’

Then, and always, Dovidl insisted that he depended more on me than I on him. He had been, in his way, as lonely as I was, cut off by his talent from other people. With me, he could be a normal boy – or as normal as his genius and my ordinariness would permit. It took a few months to balance those inequalities.

In a relationship founded on mutual dependence, there can be no secrets. Dovidl knew that I knew that he wetted his bed, picked his nose and dipped a licked finger into the bag of icing sugar on the second shelf of Martha’s pantry. I knew that he knew where I hid my KitKat stash, that I could not fall asleep without a scrap of baby-blanket wound around my toes and that, once the frost set in and Mrs Hardy had been driven indoors, I had taken shamefully to peeping through the keyhole of the maids’ room in an intensified pursuit of naked flesh.

‘It’s not safe,’ he said, catching me one evening as Florrie was getting ready for her weekly night out.

‘What would you do?’ I demanded.