Nicole (Agnes Soral) is sent up the river for infanticide in this routine woman-in-prison feature. There she meets Marthe (Annie Girardot), a fellow murderess who receives special treatment from the warden Dessombes (Marie-Christine Barrault). The warden frames Nelly (Bernadette Lafont) for drug possession and has her thrown into solitary confinement. Sabien (Corinne Touzet) is a newcomer convicted of armed robbery who latches on to the lesbian Lucie (Milva), a longtime prisoner slated for release.
After her brother was killed by a notorious all-female pirate gang, Morag dedicates her life to bringing the murderers to justice. Soon, she has become an important member of the pirate gang and has begun acquiring the loyalty of key members. Eventually, she makes her move and challenges the leader, a demi-god, known as "The Daughter of the Sun."