All the writing that comes off the Game Board will come true

Danny and Walter are two brothers who hardly get along, despite the fact that their elder sister attempts to ignore them. Despite their squabbles, the brothers manage to work together enough to play Zathura, an archaic mechanical board game. After their first move, however, they discover that the game has allegedly thrown them, their sister, and their whole house into outer space. Furthermore, the brothers conclude that the only way to return home is to complete the game. However, with practically every move, new threats emerge as the siblings learn to collaborate in unexpected ways as they understand how much they mean to each other.