EW cover: Matt Damon and Michael Douglas for "Behind the Candelabra"

HBO's big Liberace movie with Matt Damon and Michael Douglas debuts Sunday, May 26th, but Entertainment Weekly has an exclusive behind-the-scenes look in this week's issue.

Behind the Candelabra is based on Thorson’s 1988 memoir about Liberace’s over-the-top world of palatial houses, extravagant clothes, and secret affairs. (Liberace never publicly came out as gay before dying of AIDS in 1987.) It’s a world that Douglas actually witnessed first-hand, since his father, actor Kirk Douglas, was once Liberace’s neighbor in Palm Springs. “I remember meeting him just in passing, in his convertible with the top down — his hair not moving,” says the actor, who also got advice from one of Liberace’s close friends, Debbie Reynolds, who plays his mother in the film. “She just told me, ‘[Your voice] can never be too nasal.’”

The movie is also Douglas’ first role since his cancer diagnosis in 2010, and the actor tells EW that beating the disease and returning to acting has been therapeutic for him. “It was great to get back,” he says. “It gave me a new appreciation for what I do, taking advantage of it.”