Lena supports Brandon as he unloads a long-held secret that could tear his family apart. Callie brings Jude for a visit with the Quinn family in the hopes that Jude will no longer feel so threatened by this other side of Callie's life. Meanwhile, Jesus is torn between feelings of guilt over his failed relationship with Emma and pressure to prove his loyalty to Hayley. Mariana's dance team prepares for an upcoming competition, and her insecurities threaten to get the best of her
The episode starts with Jesus banging on the bathroom door, asking Mariana to come out. Meanwhile, Callie and Stef having a conversation about Callie and Jude spending a day with Quinn family so that Jude doesn't feel uncomfortable about the Quinn family. Later, Lena goes to Brandon and says it's time to "tell them" since Brandon's siblings are going to be out of the house.
At the school gym, Jesus and Emma are at wrestling practice, and they argue over Jesus's relationship with Hayley. At Mariana's dance practice, Kaitlyn tells the team one member will not be able to go for competition. Mariana feels threatened by this.
Callie and Jude reach the Quinn's yacht, and they meet the Quinn family. Jude tells Callie that she and sophia look alike.
Stef comes home and sees Lena and Brandon waiting for her in the living room. Mike also arrives. After some build up, Brandon tells them that he slept with Dani. After this, Stef and Mike get into an argument, and Lena tells them to behave sensibly.
At the yacht, Robert asks Jude to try and steer the ship in an effort to connect with him. He also tells Jude that he will never try to replace his father.
The scene then cuts to the dance practice. Mariana struggles with the dance. When Tia tries to teach her though, she get into an argument with Tia by saying that "you dance so well that you make the rest of us look bad."
Back at the house, Stef comes to Brandon and tells what Dani did to him was illegal since Dani was an adult and she should have stopped this. According to Stef, Dani needs to be prosecuted, but Brandon refuses to go along with the prosecution.
The scene then cuts back to the Quinn yacht where Sophia and Callie talk about their schools. Sophia says she hates her school, Archefield. When her mom defends the school, Sophia says she had always hated Archefield. Later, Jude calls Callie, and she leaves. As soon as Callie leaves, Jill tells sophia that,"I know you are trying to impress Callie, but being rude to your mother isn't a way to do it."
Back at the Adams Foster's house, Mike tells Lena that Brandon never liked Dani and could be making this up to get rid of her. Mike wants to talk to Dani. Afterwards, Mike and Stef get in an argument again.
At school, the dance team talk about parents since Hayley's parents are getting a divorce. Mariana tells them she's adopted and then suggests that she can with Lena try to convince her to allow them to fundraise.
The scene then cuts back to Callie and Jude's trip with the Quinns. Callie, Roobert, and Sophia are going to sea ship store, but Jude does not go with them. He tells them he is seasick, and Jill stays behind to keep him company.
Later on the motor boat, Sophia and Callie discuss "what if" Robert had stayed with Callie's mother. Callie brings up that Sophia would have never been born and Sophia ponders that maybe it isn't a bad thing.
Back on the yacht, Jill and Jude talk about the Fosters. Jill tries to interrogate him on why Callie had run away.
At school, Mariana calls Lena and tries to convince her to allow fundraising for the dance team. Lena refuses. Mat then runs into Mariana and, after some talking, encourages Mariana to practice her dance some more.
Back home, Stef complains to Lena about Mike wanting to hear Dani's side side of the story. Lena tells her not to be so hard on him and herself.
Back at dance practice, Mariana approaches Tia and apologizes. Tia then agrees to help Mariana with the dance.
At the Adams Foster's household, Stef comes to Mike and apologizes. They talk, and Stef says "although Brandon has made some bad decisions, he is sixteen. Mariana is almost sixteen what if this would have been Mariana who slept with an adult man?" Mike immediately answers he would have locked the guy up. Stef then question why Brandon is any different.
On the yacht, Sophia and Jude are sitting while callie looks at her mother's pictures. Robert and Callie talk about Callie's college fund and her own plans for college. Robert requests her to let him pay her college tuition, and Callie thanks him. Jill then approaches them and suggests it's time for them to go.
After Jesus returns home, Hayley comes to Jesus and tells him her parents are getting divorce, and she doesn't want to be alone. This leads to Jesus canceling his dinner with the wrestling team.
Elsewhere in the house, Mike comes to Brandon. Brandon apologizes again and Mike warns him about drinking and says that Dani has to be punished.
Upstairs, Mariana asks Jesus about the dinner to know if he won the "most improved" improved award. Jesus tells her he did not go because of Hayley's parents are getting a divorce. Mariana is surprised and tells him Hayley knew about the divorce months ago.
In Jude and Jesus's bedroom, Callie asks Jude what he thought of the Quinns Jude admits he wished she had never found out about them. However, he also adds that this situation cannot be changed and that the Quinns are nice people.
The scene is cut to Sophia and Robert walking side-by-side. Sophia wonders if they could adopt Callie. Robert tells her they would not need to adopt her. Sophia thinks Callie can learn to love them as easily as she learned to love the Fosters.
At Mike's apartment, Dani gets arrested. The last scene of the episode takes place in Brandon's bedroom where Stef and Brandon are laying together in Brandon's bed.
- Jude makes a comment that Callie and Sophia look alike. This is somewhat an allusion to the fact that sometimes, in real life, fans confuse Maia for Bailee and vice versa. Both actresses have made note of this fact that they do look like each other.
- The name of the Quinn family's yacht is QuinnTessence.
- Jude, for some unknown reason, is afraid to get off the yacht and on to a smaller motor boat.
- Mat reveals to part of Anchor Beach's concert band.
- While Dani was arrested in the end of this episode, it was never revealed what happened to her.
- This episode mentions that Callie has been living with the Fosters for six months. Although, it's most likely she's been living with them longer than that. Keep in mind, Lena was 20 weeks pregnant the episode before and she didn't try getting pregnant until the end of season one.
- The episode title, The Longest Day, most likely is referring to Brandon telling Mike and Stef about sleeping with Dani and Brandon's struggles that came with it. Basically, it's been a long day for Brandon.