I was exasperated with Prince Harry. My head was pounding, my jaw was clenched, and I was starting to raise my voice. And yet some part of me was still able to step outside the situation and think, This is so weird. I’m shouting at Prince Harry. Then, as Harry started going back at me, as his cheeks flushed and his eyes narrowed, a more pressing thought occurred: Whoa, it could all end right here.

This was the summer of 2022. For two years, I’d been the ghostwriter on Harry’s memoir, “Spare,” and now, reviewing his latest edits in a middle-of-the-night Zoom session, we’d come to a difficult passage. Harry, at the close of gruelling military exercises in rural England, gets captured by pretend terrorists. It’s a simulation, but the tortures inflicted upon Harry are very real. He’s hooded, dragged to an underground bunker, beaten, frozen, starved, stripped, forced into excruciating stress positions by captors wearing black balaclavas. The idea is to find out if Harry has the toughness to survive an actual capture on the battlefield. (Two of his fellow-soldiers don’t; they crack.) At last, Harry’s captors throw him against a wall, choke him, and scream insults into his face, culminating in a vile dig at—Princess Diana?