The line between sensitivity and mawkishness needs to be carefully trodden, and Morgan Matthews manages to stay just the right side of it in his debut film about an autistic maths genius. Asa Butterfield (star of Hugo) is Nathan, a teenage prodigy wary of social and physical contact, whose father dies (in an unduly dramatic sequence) at the film’s beginning. He’s brought up by his mother, played by Sally Hawkins, who does a terrific job of masking a world of worry and loneliness behind a worn smile. Nathan’s talent is fostered by a grumpy maths teacher, Mr Humphreys (Rafe Spall, also excellent), who enters him for an International Mathematical Olympiad (IMO) training camp in Taiwan.
Matthews has taken his casting cues from Mike Leigh, which is never a bad idea, and Eddie Marsan is on cheerful form as the Mathlete’s group leader. This lends it a very English feel, even when transported to Taiwan, where Nathan falls for a Chinese contestant and must deal with feelings he can’t understand in formulas. Their romance is built incrementally enough to be consistent with his condition, although it sometimes feels a little unnecessary, particularly as the film proves capable of achieving emotional resolution without it. In fact, some more interesting subplots are neglected – the burgeoning romance between Hawkins and Spall is endearingly played, and there’s a heartbreaking film-in-miniature about a fellow autistic IMO contestant (with a bathroom scene peculiarly reminiscent of something from Full Metal Jacket).
Matthews’ direction is promisingly crisp and economical, and there are some nice Lost In Translation-esque visual sequences in Taiwan. The film follows a fairly weary narrative formula – difficult genius finds love, triumphs against adversity – and it occasionally seems to be cynically working through a sentiment tick-list: Mr Humphreys was a former IMO contestant himself, whose chances were ruined by his incipient MS. Some of the dialogue about the beauty of maths is also hammy. What saves it are strong central performances and a mostly realistic, refreshing portrayal of autism. It might have been irritating, but turns out to be funny and likeable.