The Fosters kids attend a party at the Derby warehouse, but things escalate quickly when the cops show up. Lena struggles when Stef starts to become obsessed with an ongoing case at work, meanwhile Brandon’s relationship with Grace is put into jeopardy with Courtney back in his life.

Callie is torn with turning over a new leaf or supporting a cause that means a lot to her, while Jude and Taylor begin making gaming videos that earn them unwanted notoriety. Stef makes major headway in her case.

Brandon throws a party which turns south when secrets are revealed. Mariana and Jude try to convince the students to vote against their school going private.

It’s prom night at Anchor Beach. Grace’s mom has a candid conversation with Brandon, meanwhile Ximena faces a life-altering decision when ICE agents show up at prom.

Callie and her friends support Ximena in a big way at a conservative anti-immigration rally and get a lot of buzz for Ximena’s plight. Meanwhile, an unlikely source offers a key piece of evidence that may help save Anchor Beach from going private and the family celebrates Stef’s birthday.

Brandon and Grace plan the ultimate senior prank which ends up going a little too far. Mariana and Mat make a huge decision about the future of their relationship.