It's a big day for Callie as her future with the Fosters hinges on the revelation that Donald is not her birth father. What happens next could threaten to separate Callie and Jude once again. Brandon struggles to recover and come to terms with his guilt over sleeping with Dani, and big questions still remain about what Mike was up to the night Ana disappeared. Meanwhile, Jesus and Emma's relationship impacts Emma's standing with her teammates, which causes tension between them. Mariana has made a big change, much to Stef's dismay.
Things Unknown begins with Brandon’s nightmare in which he relives his recent attack. Bloody and nearly unconscious, he pulls himself into the car and the sound of the horn wakes him from his sleep. That morning, the family is happy to see that Jude’s birth certificate has arrived. Dani and Brandon have an awkward exchange of words at his school. Dani mentions moving in with Mike. Feeling guilty about their recent sexual encounter, Brandon reminds Dani of her unfaithfulness. Dani warns Brandon not to reveal their secrets to his dad as he may return to his old ways. In court, Mr. Jacob testifies to having taken care of Callie since she was 6 months old. Even with consideration to the testimony, the judge moves to deny Callie’s adoption into the Foster family pending approval from Callie’s biological father, Robert Quinn.
Flashing back to Brandon’s time in the hospital after the attack, the doctor reveals that Brandon had broken most of the bones in the hand. He says that Brandon might be able to play the piano again, but he won’t know until he tries. At school, Mariana is trying hard to fit into the dance team. With her heightened insecurities around her teammates, Mariana is consumed over the color of her hair. Mariana’s obsession worries Stef who mentions to Lena that she wants to force Mariana back to her natural hair color. Lena helps Stef understand the importance of a teenage girl’s hair. Stef updates Mike about Brandon’s condition at the police station. Mike mentions that Brandon is avoiding him and talks about his guilt over Brandon’s attack. When the topic of Ana’s disappearance comes into the conversation, Mike becomes flustered. He tells Stef to leave the situation alone.
Later at home, Callie and Brandon catch up. Callie tells Brandon that she doesn’t want to look for her biological father. She says that 18 will come soon enough and at that age, she won’t need anyone’s permission. During a nice family dinner, a social worker interrupts with bad news. The Foster's license to foster has expired, forcing the social worker to remove Callie from the home for the night. Luckily, Stef is able to catch up with a judge the next day who granted her an extension that allowed for Callie to come back home. Upon returning home, Callie decides that she doesn’t want to give social services the opportunity to pull her from the home again — Callie decides to look for Robert Quinn, her biological father. Emma confesses to Jesus that she feels isolated from her friends. Jesus attempts to quit the team for Emma, but Emma refuses and says she will take matters into her own hands. She plans on talking to the guys herself.
While at work, Callie has a strange encounter with a man. It seems that the man may be Callie’s long lost father who has tracked her down. The man leaves Callie a big tip and heads to his car where a younger looking Callie sits (likely Callie’s sister). When Callie arrives home, she apologizes to Jude for missing his essay reading. Callie asks Jude to read his essay again for her. Jude decides to read his essay to the entire family; it's a paper in which he talks about feeling stable, safe, and at home in Anchor Beach. He also talks about the importance of family and honesty. Inspired by Jude’s essay, Brandon heads to Mike’s house to talk to him about Dani. After some hesitation, Brandon’s conversation with his dad quickly shifted to his concerns with his hand injury and how it will affect his piano playing. Mike encourages Brandon to practice on the piano in Mike's home but Brandon struggles. The scene ends with a heartfelt moment between Brandon and Mike when Brandon confides in his father who comforts him through his fears and sorrows. Stef’s concerns about Ana’s disappearance are reopened at the end of the episode. After Stef learns from Brandon that Mike was drunk the night Ana went missing, Stef tracks down a witness for questioning. The witness confirms that Mike was the man Ana was arguing with before she disappeared.
- This episode started filming on February 27, 2014.
- This episode's title was revealed by Dan Ritcher, a man working for The Fosters.
- On March 10, 2014 ABC Family announced the premiere date of second season of The Fosters.
- Mariana dyes her hair blonde sometime before this episode.
- This is the first episode where we are introduced to Robert Quinn and Sophia Quinn.
- This is the first time we see Callie work at the same diner as Daphne. It is later revealed in Christmas Past that Daphne gave Callie a job application to the diner she worked at so that they could work together.
- The episode title, Things Unknown could be referencing to multiple things in the episode. It could be referencing the mystery behind Callie's birth father, the mystery behind Ana's sudden disappearence, or the fact that people don't know about Brandon sleeping with Dani. Other meanings behind this episode title are possible as well.