X+Y

At the core of this tender-hearted and moving British indie film is a fascinating relationship between a single mum, Julie (played by the superb Sally Hawkins), and her autistic teenage son, Nathan – played with equal smarts and insight by the young actor Asa Butterfield.

Director Morgan Matthews developed the film on the back of his 2007 doc about a teen maths prodigy on the spectrum. Here, that translates into the story of Nathan, a smart kid who travels to Taiwan to take part in a maths competition with other smart youngsters from around the world. But it’s the changing mother-and-son relationship back in England that really hits home – and it’s here that Hawkins (playing a very different mother from her recent endearing turn in ‘Paddington’) again proves herself one of our country’s most sensitive, thoughtful actresses.

As filmmaking, ‘X+Y’ is unassuming and not entirely remarkable, but the relationships play so sweetly and memorably: Nathan and Julie; Nathan and his mentor Martin (Rafe Spall); and Martin and Julie, as awkward as each other as they tentatively strike up a romance. It’s that awkwardness – that sense of people clumsily stumbling through life just trying to be happy and good – that makes ‘X+Y’ a little gem.