You’ve seen Stephen Root far more than you might think. He’s the shape-shifting character actor you know you recognize, but can’t place. Of course, there’s his unforgettable creation from the cult classic “Office Space”: Milton, the stapler-obsessed arsonist hidden under extremely thick glasses, stilted speech and a pocket protector. But Mr. Root has mined a number of idiosyncratic veins over the past several decades, with memorable parts in films like “No Country for Old Men,” TV shows as disparate as “NewsRadio, “Louie” and “Boardwalk Empire,” and voice work in animated ones like “King of the Hill” and “Adventure Time.”

Now, he’s the title character in Season 2 of Amazon’s “The Man in the High Castle,” a series based on the Philip K. Dick novel that imagines an America occupied by Nazis and the Japanese empire after losing World War II. A mysterious hermit in a fancy robe, the character is responsible for the central plot point: a series of contraband films depicting alternative realities that Hitler obsessively watches. “Fear and violence,” Mr. Root’s character says in the season premiere. “It’s who we are.” Sound familiar?

Over the phone from Sherman Oaks, Calif., Mr. Root, 65, discussed the show’s timely appearance and the enduring appeal of red staplers. These are edited excerpts from the conversation.

How did you prep for “The Man in the High Castle”?

I grew up reading Arthur Clarke, and Ray Bradbury and Clifford Simak, and all these guys including Philip K. Dick — but I had never read that book, which kind of astonished me. When Frank Spotnitz [the show’s creator] called, I did not get a chance to read it until after I’d shot the first episode. So I had to go completely by the script.