Stef Foster, her partner Lena Adams, a school vice principal, and a police officer, have built a close-knit family together with Stef son from Jesus, Brandon, and their allies, Mariana and an earlier marriage. Their own lives are interrupted in unexpected ways when Lena meets Callie, a teen with an abusive past who has spent his lifetime in and out. Stef and lena welcome Callie and her brother, Jude, into their home thinking until a permanent placement are available, it's simply for a couple weeks. However, life has something else available for the Fosters.