Tara Gregson is a wife and mother of two. Tara has dissociative identity disorder (DID). Whenever she is stressed, she transforms into one of her alternate personalities: wild and flirty teenager T; old-fashioned housewife Alice; and male, loud, beer-drinking Vietnam vet Buck (a fifth personality is introduced later in the season). Tara is supported by her husband Max, her somewhat troubled teenage daughter Kate and quirky, good-hearted gay son Marshall. Her sister, Charmaine, is not so supportive, often expressing her doubt about the validity of Tara's disorder.
Suburban mother and wife Tara Gregson does her best to lead a normal life while dealing with multiple personalities that include a spirited teenager called "T," a Vietnam vet named "Buck," and the perennial 1950's-style housewife, "Alice."
When her children need advice about school and sex, Tara seeks additional assistance from one of her other personalities ("Alice").
When Tara and Max can’t connect in the bedroom, Tara worries Max may be more interested in her alters than her. After gaining reassurance from her therapist Dr. Ocean,Tara plans a “sex date” with Max to get them back on track. Tara’s sister Charmaine recommends she meet her new boss for a potential mural project. As Tara prepares for her “sex date” with Max, the pressure becomes too much and she becomes “Buck.” That night, “Buck” doles out advice on women and Max ends up male-bonding with his own wife.
Tara feels the best she’s felt in a long time. She loves the mural she is working on and feels she’s found a new friend in Tiffany. That night, while Charmaine, Tara, and Tiffany are out for drinks, Tiffany decides she wants to see one of Tara’s alternate personalities and begins probing Tara in a way that turns ugly. Tiffany wakes up the next morning horrified when she finds the mural is destroyed and she suspects Tara.
Tara turns into “T” and takes off in her car. Max and Charmaine go after her, creating the perfect opportunity for Marshall to throw a party as an excuse to be near his crush, Jason. Charmaine, Max, and “T” all return to the house to discover a raging party going on -- the buzz gets killed in more ways than one.
The family is under the impression that Tara’s parents, Bev and Frank, are visiting to celebrate Charmaine’s birthday but when Frank approaches Max about taking the kids to live with them, Max does everything he can to prevent Tara from switching. At the party that night, Tara learns of her parents’ plan and is hurt that they think she is an unfit parent. Sweeping her feelings under the rug, she remains calm however, later that evening, Max wakes to find something that changes everything.
Charmaine has decided to get her breasts re-done and has asked Tara to be her caretaker while she recovers. Kate gives Marshall Love advice, telling him to play hard to get with Jason. When Charmaine wakes after her surgery, she is surprised to see “Buck” at her bedside, not Tara. While “Buck” takes care of Charmaine, she comes to appreciate him in a way she never has before.
Max has his hands full while “Alice” is out again. Marshall fears Jason’s father knows about his crush on Jason. The boys grow closer, albeit platonically. Max decides to embrace his time with “Alice,” even though he misses his wife.
Needing a break from real life, Kate and Tara head out on an impromptu road trip. Max uses this time away from Tara to search for answers about her past. That night, Tara and Kate get into an argument causing Tara to transition into “T.” “T” heads to the nearest tattoo parlor and Kate tries to stop her before she makes a permanent mistake.
When Dr. Ocean unexpectedly terminates her treatment of Tara, it throws Tara into a total meltdown at the spa with Charmaine. Upon coming home, things begin to unravel and one of Tara’s alters betrays Marshall in a way that could destroy the family forever.
Tara decides to check into an in-patient facility that specializes in dissociation. There, Tara meets a new doctor, Dr. Holden, a charismatic expert, who pushes her to recover lost memories. The facility has support groups for significant others too, but Max is wary. As Tara tries hard to delve into her past, her alters are resistant to allowing the truth to surface, and Max learns he’ll have to be stronger than ever to help Tara take the next step in her recovery.
With Max and Dr. Holden’s help, Tara meets face-to-face with an important person from her past. This meeting, while difficult, leaves Tara feeling conciliatory and expansive. Marshall finally reconciles with Tara and gives her his full support. The family, now reunited for the first time since Tara checked into the hospital, decides to partake in a family tradition – bowling but as Tara looks around at her family, she realizes she’s not who she is in spite of her alters, but BECAUSE of them.