‘What remains private’

Photos taken, back in the faintly more lived-in of his Broadway dressing rooms, Mr. Hiddleston opened the window to let in some Midtown air — and when you’re as tall as he is, 6 feet 2 inches, opening it from the top of the window frame is easy enough to do. Then, making himself an espresso with his countertop machine, he sat down to talk at length.

“I’m always curious about the presentation of a character’s external persona versus the interior,“ he said. “What remains private, hidden, concealed, protected, and what does the character allow to be seen? We all have a very complex internal world, and not all of that is on display in our external reality.”

He can tick off the ways that various characters of his conceal what’s inside: Loki, with all that rage and vulnerability “tucked away”; the ultra-proper spy Jonathan Pine, in “The Night Manager,” “hiding behind his politeness”; Robert, a lonely man wearing “a mask of control” that renders him “confident, powerful, polished,” at least as far as any onlookers can tell.

In “Betrayal,” each of the three principals has an enormous amount to hide from the people who are meant to be their closest intimates. It’s a play about power and manipulation, duplicity and misplaced trust, and what’s so threatening about it is the very ordinariness of its privileged milieu. This snug little world that once seemed so safe and ideal — the happiest of families, the oldest of friends — has long since fallen apart.

But to Mr. Hiddleston, Pinter’s drama contains two themes just as significant as betrayal: isolation and loneliness.

“The sadness in the play — it’s not only sadness; because it’s Pinter, there’s wit and levity as well — but if there is sadness in the play,” he said, “I think it comes from the fact that these betrayals render Robert, Emma and Jerry more alone than they were before.”

Trust and self-protection

One-on-one, Mr. Hiddleston was more cautious than he’d been during the photo shoot, surrounded then by a gaggle of people affiliated with the show. Still, when I asked him about betrayal, lowercase, he went straight to the condition it violates.