Stef Foster, a dedicated police officer, and also her partner Lena Adams, a school vice principal, have assembled a close knit, loving family with Stef son from their adopted allies, Brandon, and an earlier marriage, Mariana and Jesus. Their lives are interrupted in unexpected ways when Lena meets Callie, a hardened teen having an abusive past who's spent her life in and out. Lena and Stef welcome Callie and her brother, Jude, into their home believing it's just for a couple weeks, until a permanent placement are available. However, life has something available for the Fosters.