The rose beds in St James’s Park were by the lake, bursts of Ophelia and Pascali and Rose Gaujard. He leaned forward, studying with an expert’s eye the colour lustre and feeling the texture of the leaves. Growing roses was Wilson’s hobby and he liked to see a naturalness about their arrangement, not this patterned rigidity, as if they were sections of some jigsaw puzzle. But over-arranged or not, the blooms were better than his. It had to be the soil in Hampshire, full of chalk. When he got the chance, he’d talk to the gardener about increasing the compost to balance. Wilson smiled at the thought; he was going to do so much, when he got the chance.

Distantly, somewhere in the direction of the Mall, a clock bell chimed and he set off towards Whitehall. For a man who until five years before had commanded a Gurkha regiment and been seconded to intelligence with a reputation for efficient discipline, Wilson’s appearance was a personal contradiction. Careless of the obvious amusement it caused within his working circle, he wore a deerstalker, because it had flaps he could bring down over his ears in the winter and after so much time in India he suffered from the cold. The suit was good but neglected, thick tweed – again for the cold – but the trousers were absolutely without crease: although there were lots of the wrong sort, crimped tiredly behind the knees and elbows. The overcoat, of forgotten fashion, was too long and over-padded at the shoulders and cuffs, and again at the elbows the wear was obvious; in another six months, it would be threadbare.

He was bonily thin and the face was hawkish, big-nosed, with sharp, attentive eyes. Greying hair escaped from beneath the hat, like a plume, heightening the bird-like appearance. He moved awkwardly, limping where the left knee refused to bend. Wilson had come unscathed through Europe, Korea and Aden but almost lost his leg when a polo pony fell and rolled on him in Calcutta. For years it had irritated him, because of the physical hindrance, but now he was only aware of it in the coldest weather, when the ache settled deep in his calf.