“A mistake. MacDonald has his head in the clouds if he imagines The Bear will turn cuddly simply because they share a theoretical conviction. Belief was, The Game was finished with the Anglo-Russian convention seventeen years ago. But then the Reds came in and tore up all the treaties and back we went. Lenin—or whoever’s in charge while he’s ill—is buying time to sniff out our weak places, and will very soon be nudging through the passes like the Tsar before him. Our enemy may have changed his hat, but the Bolsheviks want a Communist East as much as the Tsar did, you can count on it. They won’t settle for the Congress Party—as far as they’re concerned, Gandhi’s worse than we are, a religious reactionary. And since the Bolsheviks will assuredly look to Tibet as a potential point of entry just as the Tsar before them did, we need O’Hara back on the force. True, Tibet has been receiving our own overtures of late—our giving the Dalai Lama shelter in 1910 saw to that—but whether the Russians or the Chinese get to Lhasa first, we’re going to need Tibet, and they us. We’re sending a political officer out this summer, but that’s all bells and whistles. We need someone who can see outside the diplomatic circle, and O’Hara knows the ground as a tongue knows its teeth.” He paused, to watch a pair of small black-headed birds dive at the fountain, and gave an almost imperceptible sigh.

“Still, that is not the main consideration here. What it boils down to is, O’Hara’s one of ours, and we want to know where he is.”

“And, perhaps, to know if he actually is still ‘yours’?”

Nesbit stood abruptly, taking three quick steps to bend over a fairly unexceptional flower. When he spoke, his voice was even but taut. “I refuse to believe that O’Hara has turned coat. I worked with the man. He is the King’s man to his bones.”

I waited for Holmes to agree, but he said nothing. Clearly, he had been rethinking the question since his vehement declaration in Mycroft’s rooms three weeks before. It sounded to me as if he was no longer quite so certain of Mr O’Hara’s bone-deep loyalties.

Holmes allowed the silence to hold for a while. Nesbit prowled up and down, gravel crunching under his soft shoes, until Holmes spoke.

“How many other agents have you lost in recent years?”

“That depends on what you mean by ‘lost.’ ”

“Any of the word’s definitions will do,” Holmes said irritably.