Life is shaken up once again for the Kennish-Vasquez family when a woman from Angelo's past surfaces, claiming to be pregnant with his baby. However, only Bay and Toby know. Kathryn urges John to consider running as the Republican Party candidate for the Kansas state senate. Meanwhile, Bay is accused of cheating on her French exam and decides to attend Carlton. Daphne is still upset after all that happened with Jeff and snaps at Travis. She later apologizes and the twosome plot to start up a food truck business of Daphne's very own.

Bay enrolls in an experimental immersion program at Carlton for hearing students who have been learning sign language. She meets Teo, a fellow program participant, and finds herself on the outs with Natalie, who bullies her because she is hearing. John and Kathryn inform the family of John's plans to run for state senate. Elsewhere, Toby embarks on a romance with Nikki, but pulls back after Emmett shows him a distasteful picture of her on the Internet. Angelo tells Regina about his possible unborn child and Regina has a run-in with Lana, the other woman, in an elevator. Daphne opens her food truck for business, but is uncomfortable with decisions John is trying to make for her. A boy from her old neighborhood is upset when Daphne brings her truck to East Riverside.

Daphne gets the truth from Travis' mother regarding his so-called problems at home. Regina runs into an old friend, Zane, while out with Kathryn. John sees an attack ad on his campaign involving his wife's radio interview. Toby brings Lana to the Kennish house for dinner and she lets something slip to an immigration enforcement agent about carrying Angelo's baby.

Daphne takes on more than she can handle while venturing into new territory. Toby goes to his grandfather hoping for a college recommendation. Kathryn volunteers to direct a play at Carlton. Regina sees Zane again.

Bay hosts an anti-Valentine's Day party and invites her hearing and deaf friends, leading Noah and Travis to get into a heated argument. Angelo and Lana agree to a truce to chaperone the party. Regina butts heads with John and Kathryn over how to handle the situation with Daphne's food truck.

Daphne breaks up with Travis. Afterwards, the police find the man who robbed the food truck but Travis lies when he is asked to ID the man. Daphne finds out that Travis wants personal revenge against the guy. Meanwhile, the Kennish kids are roped into helping out with John's campaign. Toby meets Elisa, a volunteer who turns out to be the daughter of the opposing candidate. Bay tells Emmett that she's in a new relationship, but he kisses her anyway. Regina is fired from her new job after the first day and turns to alcohol after being sober for many years.

While Toby bonds with Elisa, discord breaks out at Carlton when the deaf students oppose the pilot program for hearing students, leaving Daphne feeling caught in the middle. After she talks to the school board, she tells Kathryn that they have decided to close Carlton. Meanwhile, Bay tells Regina's old boyfriend Zane about Regina's alcohol abuse and Zane then tells Regina. Regina confronts Bay about telling Zane and angrily scolds her for it. Bay is severely hurt but forgives Regina for her outburst after she apologizes. The two then decide to keep it secret and Regina promises to go back to her meetings and get help. However, she goes back on her word when she leaves a voicemail for her sponsor and then deletes the message instead of sending it.

Daphne leads her classmates in a protest against the closing of their school. Bay's efforts to join them are met with resistance. The uprising horrifies the parents and puts relationships at risk including Daphne and Bay's. Daphne finds out that Regina started drinking again. Melody is offered a position on the School Board.

Daphne and the students of Carlton School for the Deaf find out if their protest will keep the school open and deaf. Lana goes into labor; Toby makes a surprise announcement; and John's campaign for office ends unexpectedly. Meanwhile, an intoxicated Regina shows up at Angelo's, and Emmett tells Bay about the kiss between Daphne and Noah.

Regina returns early from rehab, only to find that Daphne has grown closer to the Kennish family. Bay runs into her ex-boyfriend Ty; Travis and Emmett take advantage of Melody's absence and Kathryn and Nikki don't see eye to eye. Bay begins working at her dad's office.

Bay begins to reconnect with Ty but then learns shocking news about his experiences in Afghanistan. Toby and Travis both seek a managerial position at John's car wash. Kathryn and Daphne have a hard time coming to terms with Bay's desire to stay with Regina. Kathryn and Daphne become tennis partners in a tournament at the country club.

Toby and Nikki's relationship is strained by work and wedding planning so Bay tries to help Toby by booking a gig for Toby's band for the carnival to give him a temporary reprieve from the demands of adult life. Regina and Bay's messiness frustrates Angelo when he comes back from searching for his baby. Kathryn is unnerved by Adrianna's frequent visits; and Jace introduces Daphne to a new adventure.

In an alternative reality dreamt by John during his heart attack, Regina reveals the switch as soon as she learns of it. John sues her and wins exclusive custody of both three-year-old girls, obtaining a restraining order against her. Daphne Kennish is given a cochlear implant and 13 years later has turned into a typical "Buckner brat" with a C average who is best friends with Simone Sinclair, sleeps with college frat men, and steals her parents' credit card; while Bay has become an adopted, motivated, A-student wallflower. Toby retains his gambling problem. Kathryn has become a romance novelist and is sleeping with Chip Coto. Bay meets Emmett and with his help finds out about Regina. Daphne and Bay meet Adrianna and find out that Regina has died on their birthday, then angrily confront John. The dream ends with John again collapsing in the kitchen with a heart attack; he wakes up in the hospital, grateful to Regina for helping save his life.

Bay meets some of Ty's soldier friends, including an army medic named Aida whom Ty has slept with. Angelo offers Regina help in bringing in some business. After a family emergency, the Kennish family is going through some changes. John must face the reality of his situation. Daphne is torn between her family and her interest in being with Jace. The episode ending with Bay and Ty in Ty's room and Ty blows out the last candle and they sleep together.

A gay couple is introduced. Angelo invites Bay to join him at a pivotal meeting concerning the custody of his new baby. This tests their relationship when she originally declines to go, but Ty convinces her to go. When Daphne and Jace uncover Senator Coto's corruption and shameless philandering, they must decide what to do with the confidential information. Meanwhile, Nikki discovers that Toby and Simone have been in touch; and Emmett and Travis try to set Melody up on a blind date.

Bay decides to put on Deaf Day at Maui to bring in more customers, since the park has been losing business. She gets help from Emmett, which causes problems when Ty sees the two of them together. Daphne finds out that Jeff is now Jace's friend's fiancé and that the two were in a long-term relationship, despite Jeff's affair with Daphne. Red flags are raised about Jace after he tries to steal a credit card and tells Jeff's fiancé the truth. Toby suggests that Nikki visit the man who killed her father in prison to get closure. John starts to mend his relationship with his father. Bay learns that Ty is about to be deployed back to Afghanistan.

Daphne worries that Senator Coto is on to her and her frustration with Jace comes to a head when Parker shares some upsetting news. Nikki confronts her mom about her dad's history. Meanwhile, John continues to find ways to pay back Regina for saving his life; and Ty and Bay go camping as Emmett's father gets a cochlear implant.

Bay and Daphne throw Nikki an impromptu bachelorette party; while a call from Simone alters the course of Toby's bachelor party. Meanwhile, Kathryn is surprised at Jennice's extravagant wedding requests; and a change in living situation leads Angelo and Regina to reevaluate their relationship.

Toby prepares for his wedding and both his parents and Nikki's mom contemplate being truthful with him. Meanwhile, Daphne is forced to own up to her mistakes regarding her blackmail of Senator Coto. Angelo realizes that his baby belongs with Victor and Leo and makes a deal to still be part of her life. Bay seeks a long-distance romance with Ty in the face of his redeployment, however Ty learns that he'll be in even more dangerous territory this time around. To protect Bay from the truth, he breaks up with her using a terrible lie – one that leads Bay straight back into the arms of Emmett.