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You can't control who you fall in love with.

That's what Joaquin Phoenix finds out in Spike Jonze's bittersweet new romantic dramedy, "Her." As outlined in a new trailer, Phoenix plays Theodore Twombly, a writer who's still recovering from a breakup when he gets an intelligent home operating system.

Soon, Theodore's relationship with "Samantha" (the voice of Scarlett Johansson) starts to deepen and evolve. "It's been a long time since I've been with somebody I felt totally at ease with," he says.

As unlikely and odd a man/machine romance may seem, the brief scenes in the trailer are heartwarming and touching. And as his friend (Amy Adams) notes, "Falling in love is a crazy thing to do. It's kind of like a form of socially acceptable insanity."

Who are we to say what love is?

"Her" also stars Rooney Mara, Chris Pratt, and Olivia Wilde, and features music by Arcade Fire. It opens in limited release November 20.
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