The odd couple scenario is taken to a playfully surreal level with Robot & Frank, an unusual and engaging character yarn which takes a pleasingly deadpan approach to the fantasy world it establishes, and provides yet another fine performance from the ever-reliable Frank Langella.

Set in a future not too far removed from now, the Frost/Nixon star plays a retired thief (and a successful one at that, given his idyllic surroundings) who is experiencing the early signs of Alzheimer’s. While his new age daughter (Liv Tyler) is away on charity work, his businessman son (James Marsden) becomes increasingly concerned with his father’s deteriorating state and purchases a robot assistant to help him with everyday chores around the house.

At first Frank is strongly against the idea, but he soon warms to his mechanical butler (voiced by Peter Sarsgaard) and realises that the robot’s skills may also offer a way to get him getting back into the breaking and entering game. The first step in his plan is to get one over on the new owner of his local library who is clearing out all the physical books to re-launch the place as a virtual community centre. Frank also hopes his scheme will impress the head librarian (Susan Sarandon) whom he has struck up a friendship with during his many visits.

If Miranda July tackled an episode of Tales of the Unexpected the results might be something close to what’s on offer here. Robot and Frank is imbued with a fluffy whimsy and doesn’t some much march, as happily float along to the beat of its own drum. The film’s gentle oddball charm helps distract from the sometimes jarring tonal shifts, and aesthetically-speaking, it bears a resemblance to the works of the aforementioned July and Spike Jonze – perhaps unsurprising given that Jonze’s regular cinematographer Lance Acord is the film’s producer. It’s easy to see where his visual influence has seeped through to the final product.

Despite what first-time filmmaker Jake Schreier brings to the table, it’s the 74-year-old Langella who makes the biggest impression here, mustering the requisite gravitas and humanity which is key to the film’s success. He’s fantastic doing his old curmudgeon routine, but there’s an ever-present sadness too, as he slips into forgetfulness and battles with self denial. With a lesser actor onboard, the film could easily have descended into an empty exercise in quirk.

Frank’s relationship with his robot companion is pitched perfectly and Sarsgaard is also an ingenuous casting choice. His deadpan delivery (vocally, think a subdued C3-P0) is entirely in tune with the film, and design-wise, the robot character resembles a muted version of that familiar futuristic sci-fi droid design, offering a minimal and functional version of your average kitchen contraption (which it is very much an extension of). Seeing human and machine leisurely traipsing down the country road on a shopping trip brings out an unexpected warmth and humour, as does the duo as they are readying themselves for a break-in.

Robot & Frank is a welcome addition to this year’s London Film Festival, and its mix of a hip knowingness and old-fashioned sentiment should see it gain a sizable fan base when it goes on general release early next year.