When some roughhousing between two 11-year-old boys named Zachary and Ethan erupts into real violence, Ethan loses two teeth. Zachary's parents, Alan and Nancy Cowen (Kate Winslet, Christoph Waltz), meet with Ethan's parents, Penelope and Michael Longstreet (Jodie Foster, John C. Reilly), to try to smooth things over. However, what starts as a polite meeting among adults descends into finger-pointing, tantrums and insults. Based on the play "God of Carnage" by Yasmina Reza.