Plot

Events leading up to the 1996 Port Arthur massacre on Tasmania in an attempt to understand why and how the atrocity occurred.

Nitram lives with his mother and father in suburban Australia in the Mid 1990s. He lives a life of isolation and frustration at never being able to fit in. That is until he unexpectedly finds a close friend in a reclusive heiress, Helen. However when that relationship meets a tragic end, and Nitram's loneliness and anger grow, he begins a slow descent that leads to disaster.

A news footage of boys being interviewed in a burns unit of a hospital after playing with fireworks is shown. One of them is asked whether he has learned his lesson not to play with them again; he replies that he would.

Nitram is an intellectually disabled young adult who lives with his parents in Port Arthur, Australia. He regularly sets off fireworks, which upsets the neighbours, and sells his fireworks to schoolchildren. His father has recently been approved for a business loan with which he hopes to buy a bed and breakfast that Nitram will help run. Nitram begs his mother to buy him a surfboard after seeing an attractive woman with a surfer, but she is exasperated and refuses.

Nitram starts mowing lawns to make money. In the process, he meets a neighbour named Helen, a retired actress and heiress, who offers to pay him to walk her dogs. The two quickly become friends, and Helen buys him a car, despite Nitram not having a driver's license and exhibiting a dangerous habit of grabbing the steering wheel when the two are driving.

Nitram becomes increasingly frustrated with life at home and tells his parents he is moving in with Helen, who permits him to stay in a spare room but insists that he get rid of his air rifle as it upsets her. On his next birthday, Nitram introduces Helen to his parents; his mother tells Helen an anecdote about a young Nitram taking pleasure in the pain he caused her after pretending to be lost.

Despite having the funds for the bed and breakfast, Nitram's father's offer is rejected when another couple makes a higher offer, and he becomes despondent. Nitram asks Helen if the two can visit Hollywood, Los Angeles, but on the drive to the airport the next day he once again lunges for the steering wheel, resulting in a devastating car crash that kills Helen and severely injures him. When questioned by police, Nitram lies that he was asleep at the time of the crash.

Nitram, having inherited Helen's decaying mansion and over half a million dollars, starts to drink heavily. His mother asks him to help his father, who is severely depressed. Nitram then desperately attempts to buy the bed and breakfast, but the new owners flatly refuse. Several days later, his father's body is found in a nearby river after an apparent suicide. After he shows up to his father's funeral dressed in an electric blue suit and hat, Nitram's mother refuses to let him attend, fearing he will embarrass her. The increasingly isolated Nitram begins to take frequent overseas vacations by himself and practises shooting with his air rifle.

While watching the news one night, Nitram sees a report about the Dunblane massacre. He then becomes obsessed with guns, purchasing an unlicensed Colt AR-15 and shotgun and ordering a handgun. One day, he drives to the bed and breakfast his father wanted to buy and shoots the owners, then drives to the café where Helen and his parents celebrated his birthday. After ordering food, he sets up a video camera, retrieves a rifle from his sports bag and opens fire on the tourists. At her home, Nitram's mother smokes, unaware of the news report of the massacre playing in the background. (thanks to Wikipedia)