By Anthony Breznican
Updated January 22, 2012 at 09:03 AM EST

Imagine if the iPhone’s Siri was a humanoid-shaped household appliance, but one with a big, beating heart in its toaster chest.

That’s the setup for the Sundance crowdpleaser Robot and Frank, which warmed up the snowy festival Saturday with its not-so-distant-future tale of an old man (Frank Langella) befriending a caretaker machine he initially loathes. (The robot is voiced by Peter Sarsgaard, with Hal 9000 coolness, and a physique akin to Honda’s Asimo.)

EW presents four clips from the indie movie, which immediately attracted a frenzy of studio buyers after the debut. Click through to watch, and get details from the premiere.

Langella stars as a cantankerous old-timer who is slowly sliding into dementia, but still able-bodied enough to get himself into serious trouble unless someone is watching closely. Since his son and daughter (James Marsden and Liv Tyler) live far away and can’t deal with the burden, they assign the nameless robot to become his servant, nurse, and companion.

Langella, an Oscar nominee for 2008’s Frost/Nixon and a Tony winner for the Broadway show, can be an intimidating presence, but here he shows a lot of fear and vulnerability, too. First-time feature director Jake Schreier tells EW that Langella decided to more or less play the character like his own personality. “About a week before we shot, he said: ‘You know, Jake, I don’t want to act this part. I just want to do it from the heart.’ It was a pleasure to watch him, in some ways, wing it. He didn’t try to craft it too much.”

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After Saturday’s screening, Langella was asked during the audience Q&A what it was like acting opposite the faceless robot. The 74-year-old stooped a little and held the microphone out to the empty air beside him — perfect height for an imaginary ‘bot. “Do you want to answer that?” he asked his invisible friend.

That’s what it’s like,” Langella laughed. “You just go into a place in your imagination. There were different voices [reading the robot lines] at different times. There were different people inside. Sometimes there wasn’t anybody, but that didn’t much matter to me because I kept thinking he was there all the time. That’s the only way I could believe in it. It was something inside my head I was speaking to.”

He lowered the microphone again to the imaginary robot. “Right?” he asked

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Susan Sarandon co-stars as a local librarian who is the frequent target of Frank’s charm. Like him, she is being outmoded, with the library ditching its vast collection of paper books in favor of digital files. It’s a depressing prospect for her, though her own robot assistant — nicknamed Mr. Darcy — is perfectly content with the change.

There are a number of twists in Robot and Frank, which we won’t spoil here, but one major plot point involves Frank’s checkered past. We learn he was once jailed for burglary, and when the robot reinvigorates him, he begins to revert to his old criminal tendencies. His new mechanical pal becomes an accomplice to various heists, including stealing some valuable antique books from the library as a gift for Sarandon.

This scene features a fundraising event for the new library, with Frank scuttling his plan to give her the purloined tomes. The humans then try to coax their respective robots into their own friendship. Let’s just say these ‘bots don’t make a love connection.

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Langella’s daughter finally responds to her father’s complaints about the robot, and shows up unexpectedly to shut it down. But her action comes a little late — the old man has already gotten quite close to the machine, and with his own mind gradually falling apart, he begins to perceive the robot’s memory as something more than just ones and zeroes.

Is there much difference between an identity housed in biological brain cells vs. an identity preserved in microchips?

While that existential question hangs over the movie, Frank is simply really, really lonely. He just wants his robot back, please.

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