Justin Timberlake and Amanda Seyfried have done what every person in Hollywood strives to do: stop the aging process. In their new sci-fi flick "In Time," directed by Andrew Niccol, the actors' characters shake up their futuristic society, where the upper crust can buy or sell the most important thing the future has to offer: time itself.

"We're all mortals and the human race needs to be structured in a way where there's no overpopulation," Seyfried told MTV News on Saturday at San Diego Comic-Con. "And we all have body clocks and when we turn 25, you stop aging, basically, and it turns off [and] then you look 25 forever. You can be however old; you can live forever if you have a lot of time."

For Timberlake's character, Will Salas, his time is nearly up when he's gifted with more time by a wealthy older man. The elite, played by Cillian Murphy and Vincent Kartheiser, aren't too keen on this, and eventually, Salas kidnaps Kartheiser's daughter (Seyfried) and they go on the lam. Why is he so frantic to try to beat the clock? "If you run out of time, you have a heart attack and you're dead immediately," Seyfried explained. "It's cut-and-dry, black and white. There's the rich, there's the poor. It reflects a lot on our actual, real society."

Niccol has put his signature seriously satiric stamp on the ideas of aging, something that really appealed to Timberlake. "That's something that I love that Andrew does. You take a concept like the fountain of youth, something we all seem to be obsessed with, and what would happen if we actually got it? If we had the potential to live forever and we looked 25 forever?" he said.

The film features a bevy of good-looking people including Alex Pettyfer, Matt Bomer and Olivia Wilde, to name a few, making filming quite an interesting process that came with this note: "Everyone may look the same age, but not everyone is playing the same age."

"All the actors in this film look the same age, but Matt Bomer, for instance, plays a character that's 105," Timberlake explained. "And so it really is a visual trip to watch."

Check out everything we've got on "In Time."

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