Jeremy Strong has, of late, been prone to transformation on-screen. In last year’s The Apprentice, he became a late-in-life Roy Cohn, the venomous mentor to Donald Trump—all bluster with a thick Bronx accent and short temper. He earned plaudits for his dedication to sinking into the role, and his first Oscar nomination. Next year, he’ll play Mark Zuckerberg—older and cannier—in Aaron Sorkin’s sequel to The Social Network. In each case, Strong told me over a recent coffee, he pored over public footage, home videos, and whatever else he could get his hands on to gear up for his performance. But while making his latest movie, the biopic Springsteen: Deliver Me From Nowhere, the actor had access to something of a cheat: The real guy was sitting right there on set.

“It’s like having an oracle that you can go directly to,” Strong said, recalling the uncommon phenomenon of seeing the man he was portraying—Bruce Springsteen’s longtime manager, Jon Landau—seated behind the monitors. Springsteen, too, was there to watch as Strong’s co-star Jeremy Allen White conjured the artist at a specific moment in his life: the recording of the album Nebraska, back in 1981. “I spent time with Jon,” Strong explained. “I drilled him with questions.” The Adolescence Emmy winner Stephen Graham, who plays Springsteen’s father in flashbacks, described Strong as “like a magpie.” “And he’s right,” Strong said; both the bird and the actor are “just collecting, scavenging for anything.