Two years after vengeful ape Koba (Toby Kebbell) led a violent siege upon mankind as part of a coup against Caesar (Serkis) in Dawn, the war for the planet continues. Any hopes of peaceful coexistence are shattered when a failed assassination attempt on the ape leader by a group of human soldiers, led by a ruthless Colonel (Harrelson), leaves numerous apes dead. Overcome with anger, guilt, and grief, Caesar embarks on a vengeful mission of his own.