In the third-season opener, the family deal with the repercussions of a bad car accident, and Stef searches for the driver of the other vehicle involved. Meanwhile, Callie continues her volunteer work; and Brandon enters a competitive music program.
Stef and Lena host a Father's Day brunch for Mike, and Jude invites Donald to the event. Meanwhile, Callie joins the Quinns for Father's Day and learns something unexpected; and Brandon lets go of some of his frustration.
Callie has doubts about trusting AJ; Stef reveals surprising news about Monte; Jude has a difficult time getting over the shooting incident.
Lena tries to get her visiting half-brother to apologize for an insulting comment he made years ago; Callie, Jude and Connor are invited to an LGBTQ prom.
Callie and Brandon go on an unplanned trip to Mexico. Meanwhile, an empty pregnancy-test box is found in the house, and Stef and Lena wonder if someone may be pregnant.
Jude throws Callie a party for her 17th birthday, and it's a much bigger bash than she expected, complete with some surprising guests. Meanwhile, Brandon's suspicions about AJ reach a breaking point; and Mariana and Callie secretly buy a car.
Stef and Lena hesitate to give their blessing when Mariana's biological grandfather tells her she must be baptized in order to be her new half-sister Isabella's godmother. Callie's actions at her birthday party are called out by Stef, and they make a big decision in order to avoid jeopardizing her adoption.
Callie is surprised to learn that Rita has a biological daughter; Stef gets a fresh lead in the hit-and-run case; Brandon confronts his mothers about tensions in the household.
The family visit Brandon to attend his music competition, and secrets surface during the trip. Meanwhile, Callie questions Carmen and Brooke's motives; and Mike observes something that may bolster Stef's theory about the hit-and-run accident.
Stef and Lena host an anniversary party for Lena's folks as tension mounts in their own marriage. Meanwhile, Callie and Brandon plan to tell their moms about their relationship.
As the third season of "The Fosters" continues, former foster teen Callie is now officially adopted into the Adams Foster family. She must put aside any romantic feelings for Brandon and does so by throwing herself into her "Fost and Found" website, even drawing the interest of an investor (guest star Kelli Williams, "Detective McLean: Ties That Bind," "Army Wives"). After his performance at Disney Hall, Brandon is approached by a recruiter from Juilliard. Mariana launches her campaign to run for junior class president while Jesus tries to hide the reason why he doesn't want to go back to wrestling school. When Mike discovers a secret his foster son, AJ, is keeping, he is torn about what to do with the information. Jude must face the fact that his boyfriend has decided to move away, and a serious medical issue for Stef results in a clash of opinion between her wife, Lena, and her mother, Sharon. Meanwhile, Sharon introduces the family to her liberal-minded friend, Will.
Brandon is upset when he learns that his shared secret with Callie is in jeopardy. Lena and Stef's mother, Sharon disagrees over how Stef should handle her diagnosis. Meanwhile, Mariana's run for junior class president heats up as the simmering resentment between her and Lexi comes to a head.
Callie is surprised to find that Jude is spending time with Jack, a quirky foster teen they met at a foster youth event. Brandon and Mat decide to write a Romeo & Juliet rock musical as their senior thesis project, but they disagree over who should play Juliet. Meanwhile, Jesus asks Ana about the identity of his and Mariana's birth father.
After Callie and Jude discover Jack is being abused by other boys in his group foster home, they turn to foster care advocate Justina to get him help. Jesus attempts to get to know Gabe at work even as Nick urges him to tell Gabe the truth about who he is. Meanwhile, Mariana is surprised when Nick asks her out.
After Stef and Lena express concern over Callie filming an endorsement in support of a foster care reform bill, Callie goes to Rita for advice. Hoping to impress Mariana, Nick turns to Jesus for advice on planning their first date. Meanwhile, Stef recovers from a medical procedure.
Brandon's senior thesis is in jeopardy when a student raises concerns about the play glorifying suicide, leaving the school honor board to vote on whether or not his Romeo and Juliet musical can be performed at Anchor Beach. Rita's (guest star Rosie O'Donnell) daughter Chloe reaches out to Callie after Rita refuses to take her calls. Meanwhile, Stef teaches a class on handling emotion as part of a Youth Outreach Program.
Jesus is upset after his plans for a low key birthday are supplanted by Mariana, who plans a huge dance party instead. Jude is excited by the prospect of a weekend visit with Connor. Meanwhile, Callie and Brandon strike a truce by agreeing not to bring their new respective significant others home or to family functions.
Mariana worries Nick will break up with her after Zoe reveals that she cheated on Mat when they dated. Meanwhile, Callie serves as a character witness for a friend trying to regain custody of her daughter; and the twins try to help their birth father.
As they perform the parts of Romeo and Juliet on the show's big opening night, Mat and Mariana are forced to face the depth of their feelings for each other. The musical performance sparks heightened emotion for members of the Adams Foster family, causing them to reflect on recent events. Meanwhile, a domestic violence call leads Stef to a tragic discovery.
A tragic loss leads Callie to make a shocking discovery, putting her in a moral dilemma; and a gift from Nick causes Mariana to feel more guilty about her and Mat. Meanwhile, Brandon reveals to his moms that Cortney has a child.