Living on his own, and divorced for 30 years, poor old Frank (Frank Langella) is getting forgetful in his upstate New York hideaway. He thinks his son Hunter (James Marsden) is still at Princeton, but he graduated from there 15 years previously. He thinks his favourite eatery is still open, though it closed years ago.

Milk is going sour on him; he ruins his breakfast cereal when he pours it in and spews it out. His kids are getting anxious. He finds some social outlet at the local library, chatting and flirting with a bemused and tolerant librarian, played by Susan Sarandon.

Oh, and it’s the near future, by the way. The occasional smarter-than smart car zooms by Frank as he walks dangerously out in the middle of the road through the woods that take him to his house. Americans driving tiny cars? It has to be the future - near or otherwise, who knows. And when his daughter Madison (Liv Tyler) phones him from far Turkmenistan she immediately hoves into view on a TV screen in his living room, where he has been dozing off on the couch.

Meanwhile, Hunter makes a 10-hour round trip to see his dad each week, denying himself weekend time with his kids, making a sacrifice. So, to sort out this problem, he brings dad a robot, folded away in the car trunk. Out steps the humanoid, which has been programmed to make sure that his elderly charge lives a healthy lifestyle. He can talk (with Peter Saarsgaard voicing) offering, as robots do, those stilted-sounding responses to the things Frank says to him. Things that are none too complimentary. Nevertheless, in the coming days, robot begins to prove himself very useful around the house.

He shaves Frank; he brings him for walks in the woods. He dusts the furniture, plants the garden with tomatoes and prepares steamed, vegetarian and rather dull dinners for Frank.

Then one day Frank has a brainwave, after he discovers that he can manipulate the robot to become his accomplice. Bored with the docile life of the retiree, Frank decides to revisit his old career as a highly expert lock-picker and thief.

What follows is light, engaging fun, as Robot and Frank settles into something like a curiously restrained, well-behaved caper movie, if such can be imagined.

There is a very clever surprise towards the coda, when someone who we think is one thing turns out to be someone else - no more will we reveal for fear of spoiler.

This discovery helps to wrap up the whole story neatly, if sentimentally (okay, then, movingly.) The film is worth it for its low key, clever strangeness.

Paddy Kehoe