Tracks (2006)

13-year-old Nico is badly beaten by his brother while playing with fireworks. To gain revenge, he steals his brother's cat. Unable to return home, he meets up with some other kids, and they head to the railway track where two of the boys commit an act of mindless brutality. Nico is compelled by the frenzied horror of earlier events to join in. As the day draws to a close, the boys break up and head home and Nico is left to contemplate his actions.