I sat him shaking on the living-room sofa, asked Florrie to brew a strong pot of coffee and phoned Father at the office. ‘Leave it to me,’ he said tersely. ‘Keep him occupied until I call back.’

Dovidl took care of that, playing the first Brahms sonata, the G major, with Steiner at the piano and me turning pages, with such an intensity of tenderness that the ringing of the hall telephone came as a resented interruption. ‘Tell Dr Steiner the order has been revoked,’ said Father, ‘and then let me speak to him.’

‘How did you fix it?’ I asked him at dinner that night.

‘A chap I know at the Home Office,’ said Father. ‘I convinced him that Dr Steiner was essential to the war effort.’

Mother barked a sardonic laugh.

‘I didn’t have to fabricate much,’ explained Father. ‘I said he is a cipher expert – which is true, he reads Icelandic runes – and that he is a former colleague of Professor Albert Einstein, which is true in the strictly musical sense. At any rate, the Home Secretary, in person, cleared him within the hour and I have taken the necessary steps to attach him to my unit.’

The skies were beginning to thicken with the growling of aircraft. We saw nothing of the battle of Britain, which was fought above Sussex and Kent in early August, spilling occasionally into south London but never north of the river, no matter how much we craved the excitement. The nearest we got to it were the newspaper front pages that we scanned as we cycled, edited to all appearances by idle hands on the sports desk: ‘Biggest Raid Ever – Score 78 to 26 – England Still Batting’.

‘Slowly as ever,’ remarked Dovidl, who had written off cricket as a futile pastime.

‘It could always get stopped by rain,’ I chirped.

‘Why is it you English treat everything as a game?’ he snapped, exposing his cultural confusion at our unchanged habits, our refusal to indulge in the rhetoric of destiny.

‘It’s not who wins,’ I shot back with heavily inculcated cultural superiority, ‘it’s how you play the game that makes the winning worthwhile.’

We had no concrete sign of the balance of war when, on 20 August, the ebullient Prime Minister, Mr Churchill, famously extolled the decisive achievement of the Royal Air Force – ‘never in the field of human conflict was so much owed by so many to so few.’ St John’s Wood remained, at this point, as untouched as Lake Zurich.