After many years of separation, landscaper and part time dealer of illegal fireworks – Anders – is contacted by his father Thomas who is about to lose the family farm. To help his father, Anders returns home and starts a larger production of illegal fireworks and begins shipping it through the family's freight company. Through the traffic of fireworks, the family finds a way towards reconciliation and forgiveness for the first time since the family tragedy twenty years ago which Anders feels responsible for.

Marie, a former housekeeper, plans an extravagant dinner party for her engagement to the household's patriarch. As preparations unfold, hidden aspects of her past begin to surface, threatening to disrupt the celebration.

14-year-old Thomas has just moved to Copenhagen with his mom. Thomas likes to draw, it's a way for him to escape from the pressure around him. In school he meets Mads and Emma. Mads likes Thomas' drawings, whereas Emma is romantically interested in Thomas and invites him home with her. Just before leaving, Thomas meets Emmas older brother, a young, emerging artist. The meeting changes something within him. Rumors start circulating about Emma and Thomas - and he doesn't deny them. Thomas can't understand his feelings, how to act in the new school or control the lies, he has created to be popular. "October Boy" is film about all the things that change us as people.