Among the dockworkers of Le Havre, Pierre Leprieur is a respected figure. Although his integrity has earned him a few enemies, most of his colleagues support him in his determination to eradicate the drug trafficking that plagues the port. On the evening of his sixtieth birthday, when he learns that his two sons, Jean and Simon, have been taken into custody in a cocaine case, his life is turned upside down. Convinced that he is the target of a plot, he asks Emma, his lawyer daughter, to help him. But the past and its darker side resurface in the form of Pierre's brother Christophe, who has returned to Le Havre after years of absence...

After Pierre's murder, the Leprieur family is shocked. Emma urges Jean to tell what he knows, but he refuses. Simon, for his part, decides to honor his promise to work on the docks. He meets the powerful union boss, Sébastien Prévost, and tries to find out more about those involved in the drug trade. While Emma discovers that their father has mysteriously emptied his bank account, Jean, under house arrest, is kicked out by his wife. He visits Christophe to take stock of their affairs...