In Her, watch Joaquin Phoenix fall in love with his machine

"I think anybody who falls in love is a freak. It's a crazy thing to do. It's kind of like a form of socially acceptable insanity."

So says Amy Adams' character (also named Amy) towards the close of Spike Jonze's mellow meditation on love and technology, (HBO, Friday at 10.30pm).

Theodore Twombly (Joaquin Phoenix; below right with Adams) is reeling from the collapse of his marriage. He meanders through a near-future Los Angeles (depicted admirably by present-day Shanghai) in a fog of misery, detached from those around him. At work he composes heartfelt, deeply personal love letters for clients unable or too lazy to express such emotions themselves and at home he distracts himself with video games and calls to sex chat rooms.

At first, Her matches the melancholic tone of 2009's Where the Wild Things Are, Jonze's bleak adaptation (with Dave Eggers) of Maurice Sendak's beloved book. This changes when Theo buys an operating system, or "OS", that is capable of learning, conversing and adapting. The OS, called Samantha (voiced by Scarlett Johansson), quickly becomes an integral part of Theo's life and the pair develop a romantic connection.

A lesser film might focus on the bizarre nature of Theo and Samantha's relationship, with the characters being regarded as freaks or outcasts. Where Jonze triumphs is in making not only their coupling seem normal, but also the technology.

Theo and Samantha's courtship illustrates how sophisticated technology becomes embedded in our daily lives. When Theo hesitatingly admits to a friend that he is dating his computer, she reacts not with shock but with interest: she's already aware such relationships exist.