To get your head round Spike Jonze's delicate new sci-fi movie, Her, you need to believe absolutely and unequivocally in the premise: that a sad and lonely man is capable of falling in love with a computerised operating system, think Siri 10 years down the line, and forming a sincere attachment.

Her Joaquin Phoenix
Joaquin Phoenix Plays A Man Seeking Love In An Unlikely Place In 'Her.'

"Delicate" is rarely a word you'll hear attributed to sci-fi movies but Jonze's masterful new film, which stars Joaquin Phoenix, is both a strange tale of human attachment and a potentially troubling insight into the future of technology.

Scarlett Johansson plays Samantha, the computer operating system designed to fit divorcee Theodore's every need. With her cracked voice and digitically generated wit, Samantha is far from the robotic, repetitive help systems we're used to today as she sets about getting to know Theodore (Phoenix) as well as possible.

Watch The 'Her' Trailer:

Though Theodore is tragically falling in love with the woman who is always there for him, ready to help out and lend a listening ear, his initial professions of affection are met with a big fat "Does Not Compute." However, she begins to learn and reciprocate his affections leading to a heart-breaking scenario when Theodore must come to terms with the fact that his true love isn't even a physical entity.

Her Joaquin Phoenix Movie
The Beautiful Film Combines Sci-Fi Technology With Tender Emotion.

For those still unsure about the basic concept of Her, the LA Times reassures: "['Her' is] Acerbic, emotional, provocative, it's a risky high dive off the big board with a plot that sounds like a gimmick but ends up haunting, odd and a bit wonderful. Her sees Jonze ('Where The Wild Things Are,' 'Being John Malkovich') come into his own as the sole writer, inflecting the film with the quirkiness that we're used to but also the depth of emotion that makes the director's films so memorable.

Spike Jonze Her
There's An Oscar Buzz For 'Her' Already: Can It Live Up To Expectation?

However, and The Verge assesses, Her "eschews the weirdness" that tinged some of Jonze's previous films and "Phoenix and Johannson do an incredible job making us believe that they are two equal entities." Framed within "the epic sweep of a science-fiction opus," critics are stepping forward to praise the innovation and daring involved in pulling off a movie that could have fallen flat if not for the back-on-form Phoenix ('Gladiator,' 'Walk The Line') who plays a fragile man seeking a human connection in an unlikely place.

Her will be released on the 10th January in the USA and the 14th February in the UK.