SAN DIEGO — In sci-fi thriller In Time, scientists have figured out a way to turn off the aging gene. But if you want to live forever, you have to pay.

“We figured out how to look 25 forever,” says Timberlake in the Wired.com video interview above. “The bad part is, what happens at that point is your body clock starts and you have a year of time to live. So basically you start running out of time.”

The timekeepers come after him, and he kidnaps Seyfried to help keep him alive. Naturally, things get complicated as their relationship develops.

“We kind of are slowly becoming closer until we are naked together,” says Seyfried.

We talk to the film’s stars about their characters, the making of the movie and their on-screen chemistry. In Time, written and directed by Andrew Niccol (Gattaca, The Truman Show), opens Oct. 28.