In the eight years since his mother died giving birth to him, Garnet (Roberts) and his sixteen-year-old sister Flower (McGregor) have lived with
their emotionally detached father, Ed (Rennie). As Flower reaches maturity, she tries to push her father to finally become a real parent to Garnet,
whose growing attachment to her has become a burden in her quest for affection. Ed reaches out by buying Garnet a BB gun, and finally starts to show affection and enthusiasm when his son proves to be a skilled marksman. But by introducing Garnet to the power of killing without context or responsibility, Ed unwittingly pushes his already fragile son further toward the edge
After Flower gets pregnant and decides to keep the baby despite Ed's vehement opposition, a rift develops in the family and Flower moves out. Garnet begins skipping school and experimenting with his father's handgun, which he steals from under Ed's bed. Despite the many signs that Garnet's state is becoming increasingly unbalanced, Ed refuses to deal with the fact that his son has serious problems... until Garnet disappears with the gun on the same night Flower goes into a difficult labor.