Lena worries when Stef returns to work; Kelsey exposes secrets from Mariana's past.

Callie meets a woman who works in the foster care system; Brandon reveals why Callie ran away.

Callie, a 16-year-old girl fresh out of juvenile hall, goes to live in the care of Lena and her partner Stef and their kids.

Everyone is celebrating Mariana's quinceanera, and the secret Jesus has been hiding comes to light, which causes tension between Mariana and Lexi.

Stef and Lena try to find time to work on their relationship, while Lexi and Jesus have to deal with the consequences of their actions.

The family is impacted by Callie's decision to run away; Mariana learns the truth about Lexi's trip.

When Jesus’s birth father, Gabe, doesn’t show up to work on Stef and Lena’s garage, Jesus takes on the job himself and gets injured in the process. An exhausted Mariana, deep into her robotics STEAM project, takes Jesus’ ADHD medicine for a boost. Callie and AJ find themselves in an awkward situation when Mike and Brandon unexpectedly come home early. Meanwhile, Stef lets Mike know that Brandon gave his hand injury settlement money to Cortney.

In the aftermath of Jesus’ fight with Nick over Mariana, Jesus is knocked out. On the way to the hospital, things take a turn for the worse, leaving him fighting for his life. Meanwhile, Callie finds herself in a dangerous situation after taking a ride with Troy and Mariana is guilt-ridden over the fact that her actions led to Jesus’ current condition.

Lena is excited that her family is coming together to throw her a 70s-themed 40th birthday party. But, when Lena’s mom Dana shares her suspicions about Stewart’s behavior, it threatens to put a damper on the festivities. Convinced her former foster brother Kyle has been wrongly convicted of murder, Callie and Aaron try to track down a witness in the case. Mariana and her female STEAM club teammates compete for an invite to the Regional Robotics Competition. Meanwhile, Jude is hurt to discover that Connor came to town and didn’t tell him, and Brandon considers drastic measures to make extra money.

Lena is shocked by the news that her dad has been hiding something that directly puts them all in jeopardy. Additionally, she uncovers a major secret that Brandon has been keeping. Mariana continues to be pressured by Nick and must deal with direct opposition from the male members on her STEAM team. Meanwhile, Jesus grows resentful of Emma’s behavior, and Jude discovers Noah has a medical marijuana card.

Callie faces a life-changing decision to take a plea deal and go to jail for three years, or go to trial and risk an even longer sentence. Even though Callie struggles with her own situation, she tries to help Diamond out of hers which becomes extremely dangerous. With only 24 hours to make a difference in Callie’s case, Stef and Mike ramp up their investigation into the Martha Johnson murder bringing in as many leads as possible. Lena confronts Drew about his campaign to make a major change at Anchor Beach Community Charter School, while Mariana rallies her fellow students to protest. Meanwhile, Jesus starts to put together the pieces about Emma.

The Fosters are getting married, but Stef is not as involved as a stressed out Lena would like.

After being given the all clear to head home, tensions are still running high in the Adams Foster household. Fragile and skittish from the school lockdown, the family sticks close, but their secrets keep them apart. Callie and Brandon anxiously wait for their moms to address their behavior in Idyllwild while Stef warns everyone to stay off their phones and computers due to the rumors swirling around their family.

In the aftermath of the school lockdown, Mariana is called out by other students who blame her for Nick’s actions. Callie is also taunted at school and her inappropriate reaction gets her suspended. But what starts off as a punishment turns into an adventure when she meets Aaron, a handsome young law student who knows nothing about her or her past.

Mariana and Jesus compete in the First Robotics Southern California Regionals, but when Mariana gets too competitive under the stress, Lena grows alarmed. Callie gets a warning from the police to stop harassing Patrick Molloy. Brandon practices for his fast-approaching Julliard audition.

As Stef and Lena stand vigil over an unconscious Jesus, he dreams of an alternate world wherein he tries to save Mariana but can’t get to her. Already stretched thin, the moms receive news that Callie is in serious legal trouble. Mariana seeks comfort in Mat’s arms, while Brandon tries to hold the family together.

Callie tries to keep to herself and focus on getting out of juvenile hall, but when she refuses a guard’s propositions, she ends up making an enemy. As Stef and Lena work to get Callie out of juvie, her biological father Robert turns up, angry for being kept in the dark. Meanwhile, Brandon’s questioning of a situation has consequences for Mariana. Jude gets a second chance with Noah, and Mike makes several life-changing decisions.

After Brandon confesses to Stef that he didn’t get into Juilliard, she decides she’s fed up with all of the kids’ secrets and removes their bedroom doors. Mariana starts seeing a therapist to deal with the trauma of Nick’s actions. While Jesus struggles with physical therapy, Brandon realizes that music might be a good way to help get through to him. Callie’s biological father Robert brings in his highly paid attorneys to handle Callie’s case, which causes a conflict with Stef and Lena.

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.

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 now officially adopted into the Adams Foster family and must put aside any romantic feelings for Brandon. She does so by throwing herself into her “Fost and Found” website, even drawing the interest of an investor.

While Stef recovers from surgery, she and Lena grow concerned when they find out Justina wants Callie to support a legislation that they know nothing about.

Callie starts her senior project of photographing the outside of her and Jude’s seven former foster homes. But, when an unexpected encounter with a former foster mother brings her inside, Callie decides to reach out to other people who have fostered her and is shocked to learn that a 17-year-old former foster brother has been convicted of murder. Stressed out by the hardships of supporting himself and Cortney, Brandon throws a house party and things take a turn for the worse. Stef and Lena offer to pay for an attorney to help get Gabe off of the sex offender registry, which is currently putting Lena’s job at risk and causing friction between Mike and Ana. Meanwhile, Mariana tells her moms that, in order to feel safe again, she wants to visit Nick and put an end to their relationship once and for all.

Stef starts a new assignment in human trafficking where she meets a teenaged girl named Diamond who is turning tricks on the streets. Lena deals with repercussions for holding an off-campus LGBTQ sex ed class for Anchor Beach students. Callie’s relentless pursuit of justice starts to impact her relationship with AJ. Meanwhile, Mariana tries to cheer up Jesus with a special project after he’s prescribed a special pair of glasses due to his traumatic brain injury.

Mike asks Brandon to move in with him, and Jesus and Lexi continue to keep their relationship a secret from Mariana.