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.