Parents need to know that Dunkirk is director Christopher Nolan's World War II movie about the real-life incident in which Allied forces were surrounded and trapped on Dunkirk beach -- and everyday heroes helped rescue them, despite the risk of danger and death. The movie's war violence is realistic and intense, with heavy bombing and shooting and many deaths (though very little blood). Planes crash in the ocean, ships fill with water and sink, and an oil slick catches fire, burning many soldiers. A teen civilian is injured, and a man walks into the ocean, presumably to commit suicide. Language includes two uses of "f--k" and one "Christ" (as an exclamation), and there's one scene with beer. Kenneth Branagh, Tom Hardy, and Cillian Murphy co-star, but there are many characters, some of whom aren't clearly distinguished from others. That, plus Nolan's time-twisting technique, can make the story challenging to follow. But it has messages of bravery, teamwork, and sacrifice, and persistent teens and adults will be rewarded with a powerful, visceral experience.