On September 12, Harry Potter film star and now Broadway regular Daniel Radcliffe paid a visit to Jimmy Fallon on The Tonight Show.

Having starred in Equus, How to Succeed in Business Without Really Trying, and The Cripple of Inishmaan, Radcliffe now returns to Broadway in the new play The Lifespan of a Fact, which begins performances September 20 at Studio 54.

“I play a fact-checker that is sent to check an article written by an author, played by Bobby [Cannavale], and this author is not used to being held to journalistic standards of accuracy,” Radcliffe told Fallon, “so I go in and make his life hell for a few days and Cherry [Jones]’ character is our editor who has to make the decision whether or not to publish the article in the end and keep us from killing each other—but it's a comedy!

“And one thing I have to say—because it will get me to see any play—is it's one act, straight through,” Radcliffe adds.

Radcliffe also talked about his upcoming film, Guns Akimbo, shot this past summer in New Zealand, as well as his obsession with American football (he’s in two Fantasy leagues).

Although Lifespan of a Fact has two shows on Sundays—a big day for the NFL—Radcliffe said, “the fear of screwing up keeps me concentrating.”

Radcliffe also stopped by The Today Show September 13, and had some words of advice for Al Roker, who's poised to make his Broadway debut next month in Waitress. Check out the clip below.