The princess chuckled. ‘She was always a fine needlewoman. But none of these girls was truly a nurse, you know. Amateurs all, some more capable than others. Some with decorative merit only. You’re looking, Captain, at the contents of the topmost drawer of the Russian aristocracy doing their bit in wartime for their country. The Empress Alexandra herself led by example and floated through the wards in cape and wimple dispensing comfort. Though I ought not to disparage their efforts — they meant well, and, in Anna’s case, acquired a genuine skill, they say. But, Captain … you do well to pick her out amongst so many beauties, all wearing an unflattering starched headdress …?’

The question was lightly put but Swinburne picked up an underlying tension. Was he being quizzed in some way? Had the photograph, prominently placed as it was, been set there deliberately as some kind of test? The captain was a straightforward man, who couldn’t be doing with traps and subtleties. His reply came at once.

‘Be assured ma’am, I’d know her face anywhere. It’s the line of the nose, like a Greek statue, and the dark eyebrows — they have the sweep of a gull’s wing. She’s the one on the far left. I’d no idea this was her world.’

The princess, who had been tugging at the pearls at her throat in some suspense, sighed with relief at his identification and stopped her fidgeting. She came to stand at his side, looking at the photograph with him, relaxed now and companionable. Whatever test she’d just administered, he seemed to have passed it. ‘Yes, Captain, that is indeed our Anna. My poor cousin Peter’s daughter. I held her in my arms the day she was born.’

He was pleased to note in her voice the tremble of an emotion she could no longer hold back, the tears gathering in her eyes, the furtive hunting in her sleeve for a handkerchief. She accepted the crisp square of linen he offered and put it to use with grace and murmured thanks. After a moment, she spoke again more brightly. ‘As a child, Anna spent many summers with us in the Crimea … she will feel at home here with me now. But I share your dismay at a world so abruptly and tragically torn from us. Anna would have made a good marriage. She could have had her pick of the finest young men of Europe. Probably not royalty but a count at the very least … a duke perhaps? Sadly now all dead or dispersed and she herself ruined beyond any hope of-’

She suppressed the alarming thought and her tone became crisp. ‘But that is all past, and we must look, as you say, to her future. You may leave her with us in total confidence. I have heard your words and understood the deeper concerns on which you are tactfully silent. I say again — I will provide the care she needs.’

Swinburne had heard the same tone from admirals and generals. There was only one acceptable answer: ‘Yes, sir. Of course, sir.’ This tiny, decisive woman he had no knowledge of and no reason to trust had, unaccountably, got under his defences. He nodded his superfluous agreement. ‘Yes, ma’am. Of course, ma’am,’ he said, and he smiled as he spoke.

Swinburne bowed and made to leave.

‘Wait, Captain!’ She hesitated for a moment, then picked up the photograph and handed it to him. ‘If you will keep it for your eyes alone you may have this — some slight reward for your care. But be discreet. We aristocrats all have a price on our heads still and are pursued. London is full of ruthless men, not a few of them our enemies.’

As he took it from her, murmuring his thanks, he caught a flash of indulgence and pity in her eyes. She’d guessed his secret in minutes. Time he was gone.