Since the death of his loving father in a car crash, Nathan (Asa Butterfield) has devoted his life to being good enough at maths to get a spot on the British squad for the International Mathematics Olympiad. For his acerbic, MS-afflicted teacher (Rafe Spall), Nathan’s single-minded obsession (he’s diagnosed early on as being on the autistic spectrum) is something that brings them together; for his devoted mother (an often devastating performance from Sally Hawkins), it’s just one more barrier between them.
It’s no spoiler to reveal he achieves his dream, but with a place on the team comes a trip to math camp in Taipei, and with these strange new surrounds come strange new friends, especially Zhang Mei (Jo Yang). But as Nathan slowly opens up to new experiences, will the pressures of the big competition ahead set him back or set him free? This story holds few surprises, though a refusal to sugar-coat the tougher issues raised – especially via another, less charming autistic student (Jake Davies) – gives this a bleaker edge than you might expect. Well, bleaker if you ignore the fact that the barely social Nathan has not one but two girls chasing after him, but his sullen teen act is the kind of thing that traditionally drives the girls wild (in movies at least), The performances here are all so strong that the story’s weak notes barely register; the only drawback is that the film can’t give equal time to everybody.