Mikhail spoke then, for the first time in several minutes, making it clear his thinking was in accord with Hanbury’s. He had Russian reasons for choosing the boy. Alexei was not merely Tsarevitch but Tsesarevitch, not simply a son of the Tsar but the Tsar-in-waiting. He was naslednik, the successor. And he had long wished to travel to Britain, where he would be made very welcome. Britain, they both believed, was the perfect place for Alexei to learn to be the leader of the next Russia, the democratic monarchy that they believed Russia could be.

If they were wrong and there was no revolution, the Tsarevitch would at least be well educated. His father would continue to be Emperor and Alexei would be more ready than ever to succeed when the time came, if his health allowed it. But, if they were right and the Emperor was overthrown, the Tsarevitch would be the one person who could draw together allies across Russia and turn the tide.

‘We need someone to take the Tsarevitch out of the country,’ Hanbury told me. ‘Someone well separated from Russia and its confounded politics. Someone who could slip past unnoticed. Someone of standing, but not of political interest. Someone the boy trusts. Weeks ago, we had earmarked Alfred Knox for that role, but he is still unwell in Petrograd with scarlet fever and we no longer have the time for him to recover.’

I knew then that I was their choice, and that this was the purpose of our conversation.

What did you decide to do?

I was in Russia to advance the interests of the United States – to open lines of communication, to progress certain possibilities without appearing to progress them. I was there to ready us for a situation that, it was becoming clear, was highly unlikely to arise.

But could it? And, if there was a revolution, could the Tsarevitch be the key to that? To a stable Russia and all of its trade opportunities? The Duma was already fragmented and would split. We knew that. We knew there would be uneasy coalitions. And we knew the Bolsheviks would, in the end, stand for none of that and seek to have it all to themselves. I could not convince myself that such an outcome would be in America’s interests in the slightest. But it was entirely possible that sufficient forces could come together around the Tsarevitch and prevent it.

I had been tasked with saving the world’s greatest autocratic line, but also saving a wonderful boy and the best hope of a nation as wide as half the globe. It took no time at all to convince myself that to act to save the boy would be acting in the best interests of the United States.

Would a man who had not lost a son of tender years have come to the same conclusion? I cannot say, for I am not he. I could not save my own son with all the medicine, prayer and tears at my disposal, but here was another man’s son whom I might save.