Fifteen-year-old Thomas Mollison (Rhys Wakefield) and his family are have just moved to Sydney, Australia. His father Simon (Erik Thomson) is a soldier, and they are used to living in new places. His mother Maggie (Toni Collette) is pregnant, and she spends a lot of her time looking after Thomas's older brother Charlie (Luke Ford) who is autistic; he communicates some through sign language but is unwilling to speak. Their new neighbors stare rudely as Charlie rocks back and forth in the yard pounding a wooden spoon on the ground and groaning. When Maggie is told by a doctor that she needs to stay in bed until the baby is born, her husband and younger son are put in charge of looking after Charlie. That is no easy task since he likes to bolt out the door and run down the street in his underwear.
At school, Thomas wants to fit in and make friends, but he wonders if that is possible given that his classmates make fun of the school bus carrying Charlie and other mentally challenged kids to their school. In swimming class, Thomas is attracted to Jackie (Gemma Ward), and she seems to take an immediate liking to this awkward swimmer and archetypal outsider. But he's embarrassed by an incident involving his brother at her house.
Although others in the neighbor don't like all the commotion Charlie causes (one of the neighbors even calls the police), Jackie takes a genuine interest in him. After several dates, Thomas invites her to attend his family celebration of his birthday. But Charlie spoils the evening, and Thomas explodes in anger. It is a frightening scene which conveys his rage at the fact that his brother will never be normal.
The Black Balloon is written and directed by Elissa Down who grew up with two autistic brothers. That, no doubt, explains why the drama has such an authentic feel to it. We see and respect the courage, love, and patience needed to raise a mentally challenged child, and we wince at the cruelty and insensitivity of adults and youth who ridicule Charlie and others like him. Thanks to the support and open-mindedness of Jackie, Thomas is able to renegotiate his relationship with Charlie. Their new bond is saluted in a scene near the end of the film which touches the heart.
