Nathan (Butterfield) struggles to connect with people, pushing away his mum (Hawkins) and those who want to be close to him. Without the ability to understand love or affection, Nathan finds comfort and security in numbers and mathematics.

Mentored by an unconventional teacher (Spall), Nathan’s talents earn him a place at the International Mathematics Olympiad. But when the team go to train in Taiwan, Nathan is faced with unexpected challenges, not least the new and unfamiliar feelings he begins to experience for a beautiful competitor.