Patryk and Jurek are as much friends as rivals in the small Russian-occupied Polish village where they live. When, in August 1914, Patryk finds an old button on the forest floor, Jurek becomes wildly jealous. Not long after, World War I comes to Poland, bringing one invading army after another to the village. Jurek devises an exciting dare among the seven boys in their pack: whoever steals the best military button will be Button King. The boys agree. The contest is on. The competition escalates from stealing uniform buttons on a wash line to looting the bodies of dead soldiers to setting up an ambush. Leading the charge is Jurek, who will do anything to be Button King. It's only Patryk who tries to stop Jurek's increasingly dangerous game before it leads to deadly consequences.