Thomas is about to turn sixteen and start yet another new school but his problems are a little more complex than just being the new boy. His older brother Charlie is autistic and suffers from ADHD, so Thomas is often forced to be more keeper than playmate to him. The unfairness of his situation is apparent – after all how many teenage boys are used to their older brother fouling himself or running away? And with their mother under doctor’s orders to rest in her final months of pregnancy, Thomas’ responsibilities to look after his brother are only increasing.

The Black Balloon handles Thomas’ resentment of his helpless elder brother, a selfish but very human reaction, with no little skill and sympathy, thanks to a sensitive script and a great performance by Rhys Wakefield. Toni Collette, meanwhile, turns in a fine, measured performance as the boys’ mother, Maggie, struggling to cope with the vicissitudes of life in suburbia as the conflict between her two sons threatens to tear her family apart. Playing Thomas’ first love Jackie, Gemma Ward – whom director Elissa Downs cast in her first film role in 2001’s Pink Pyjamas, and who is far better known as a model than actress – brings a sweetness to proceedings which balances the harsh realities elsewhere in the film.

So often films featuring characters with learning disabilities are either over-sentimental or overly tragic but here, there is an irrepressible joy for this family, who just get on with life. Charlie’s physical strength and wilful determination are both challenging and potentially threatening (scenes between Charlie and Thomas’ girlfriend are deliberately tense) but this is essentially a hopeful and optimistic story where love and kindness can tame, or at least restrain.