Lena meets troubled teen Callie and asks her to temporarily move in with her family in the series premiere of this drama about a lesbian couple heading up a multiethnic family comprised of a biological son and a few adopted children.
Lena and Mike disagree about whether to punish Brandon. Elsewhere, Jesus tries to cover for Mariana and puts his health at risk in the process, while Callie gets blamed for Mariana's transgression; and Jesus and Lexi embark on a secret relationship.
Mike invites Brandon to move in with him, which leads to an argument between Stef and Brandon. Meanwhile, Mariana objects to Jesus dating Lexi; and Callie's journal assignment sparks memories of a dark secret from her past.
Lena wants Mariana's quinceañera to be perfect, but Mariana uncovers a secret that may ruin her day. Meanwhile, Lena's mom visits; and Stef reminds Brandon of the dating rules when she observes his and Talya's friction over Callie.
Passion takes Jesus and Lexi by surprise, and soon they realize there may be consequences. Meanwhile, Brandon objects to Callie's budding romance with Wyatt; Stef and Lena's friends hit a snag in their relationship; and school bullies target Jude.
Lexi's conservative parents join the Fosters for dinner, and Stef's traditional-minded dad drops by. Meanwhile, Callie attends a therapy group for foster kids; Wyatt throws a wild party at his childhood home; and Brandon has an important piano audition.
Tension between Jesus and Mariana erupts in a big feud. Meanwhile, Lexi's parents attempt to keep her away from Jesus; Callie tells Brandon about a difficult memory from her past; and Jude tries to impress a new friend from school.
Jesus meets his biological mom, but it doesn't go well. Elsewhere, Lena's worldly ex-girlfriend visits town; Stef worries about Mike's excessive drinking; Brandon struggles to impress his piano teacher; and Tayla finds herself in a mortifying situation.
A loved one lands in the hospital, and the extent of Mariana and Jesus' lies affect everyone. Meanwhile, Callie opens up to Brandon about her mom's death and her life as a foster child; and Wyatt warns Callie that she's growing too close to Brandon.
The family gather for Stef and Lena's wedding, which Lena's dad plans to officiate and Stef's dad plans to skip. Meanwhile, Callie's faced with a tough decision in her case against Liam; and Callie and Jude get some good news.
Jude and Brandon feel guilty about Callie running away, and other family members are confused about Callie's actions. Meanwhile, Mariana stumbles upon the real reason for Lexi's impending trip to Honduras.
A stern foster-care worker supervises Callie. Meanwhile, Brandon searches for Callie after he confesses why she ran away; Mariana gets involved with the school play; and Jesus struggles with his new medication and tries out for the wrestling team.
Lena worries about Stef going back to work and Jesus undergoing hazing on the wrestling team. Meanwhile, Mariana and Kelsey put their friendship at risk because of a boy; and the threat of severe consequences doesn't keep Callie and Brandon apart.
Callie visits the family and things get awkward between her and Brandon. Meanwhile, Rita informs Stef and Lena of Callie's plans; Jude has to decide if he wants to proceed with the adoption; and Lena wants Stef to make amends with Frank.
Painful memories haunt Callie and she reevaluates her life when she visits the Fosters' home for a family gathering. Meanwhile, Jesus gets close to a female teammate; and new developments in the shooting case worry Mike.
Callie makes a bold change to better her future, while Brandon makes a transition that upsets her. Meanwhile, Stef faces an ethical dilemma when she testifies in Mike's case; Jude gets a cryptic message; and Mariana tries to make an impression on Chase.
Callie's photography skills cause unintentional trouble for her pal. Meanwhile, Brandon has regrets about making a deal with a shady classmate; Mariana faces the fallout from a stunt she pulled; and Jesus and Emma have a tense wrestling match.
Pressure to make a hard decision mounts for Jesus and causes him to get distracted while wrestling. Elsewhere, Callie wants to help Brandon, but doing so means hurting a friend; and Mariana realizes Zac's home life is difficult.
Callie feels conflicted after meeting with her dad, and she worries how this will affect Jude. Elsewhere, Jesus has a hard time at school without his ADHD medicine; Zac's mom extends a surprising invitation to Mariana; and Lena and Stef make a big decision after getting insight from a friend.
The Foster teens get ready for their school's winter ball. Meanwhile, Callie's old friend tries to reconcile with her; a past mistake haunts Brandon; Ana delivers some troubling news to Stef; and Zac's mother seeks a conversation with Lena.
In the first-season finale, devastating news is revealed to the Fosters as Callie and Jude prepare for their adoption. Meanwhile, Mariana stands by a friend who faces a hard decision; Brandon makes another poor choice; and Jude is asked out on a date.