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."

Tara feels like a failure as a mother when she is unable to counsel her children about school and sex, so she turns to her perfect-homemaker personality "Alice" for help.

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.

Season two opens with a bang as the Gregsons' neighbor commits suicide and the family unexpectedly is given responsibility of the house. Now well and dissociation-free for several months, Tara sets out to make new friends with Max's help. Marshall struggles to fit in at school while Kate lands a new job. Nick pops the question to Charmaine

Tara realizes her alternate personalities are emerging again, but keeps it a secret. Newly engaged Charmaine asks to move in with Tara and her family. Max decides to take on a new project by buying the neighbor’s house to flip it. Kate meets a mysterious older woman, Lynda (Viola Davis), while Marshall begins a new relationship… with a girl

The family discovers the truth -- Tara’s alternate personalities are back. Buck’s actions have brought serious consequences that unleash a new side of Max. Neil finds out about Charmaine’s engagement. Marshall and Courtney begin to experiment as Kate grows closer to Lynda.

Tara sets out to find a new therapist as Max struggles to come to terms with Buck’s affair. Marshall and Courtney take their relationship to the next level. Tara and Max disapprove of Kate’s friendship with Lynda. Charmaine tells the family some big news. A new alternate personality is born.

Max’s violent outburst comes back to haunt him. Tara learns she is now able to be aware of what her newest alternate personality, Shoshana, does. Kate’s music video is an internet success. Marshall decides he has to break up with Courtney. The doctor gives Charmaine surprising news about her pregnancy.

A tornado brings some long-covered secrets to light when Tara's alter Shoshana takes over.

An upcoming visit from a social worker has its effect on Max. Disapproving Kate's friendship with Lynda, Tara interferes while Neil learns that Charmaine is pregnant.

Tara and Lynda make preparations for their art show. Kate sets up a new business, while Lionel and Marshall's friendship deepens. In the meantime, Charmaine struggles trying to balance Neil and Nick.

Tara starts working on a family portrait in order to re-connect with her family while Max tries to get away from Pammy.

Tara and Charmaine discuss Tara's childhood memories with their mother and Max holds an open house after re-modeling their neighbor's house.

Tara and Charmaine pay a woman who appeared in Tara's memories a visit, while Kate tries to change herself for her new and much older boyfriend.

On the day of Charmaine and Nick's wedding, long-held secrets come to light, while Kate and Marshall accidentally make a discovery of consequence.

Max is worried when Tara returns to college to finish her college degree. Meanwhile, Charmaine with a baby on the way is avoiding a commitment to Neil, Kate tries to figure out a plan for her future and Marshall and Lionel sign up for a filmmaking class.

Her psychology professor humiliates Tara when she transitions in his class. Meanwhile, Kate considers giving English lessons in Japan and Max gets a business offer.

The stress of juggling school and Charmaine's baby shower causes Tara to transition, with negative consequences for Charmaine. To sell the family business, Max must get the approval of his eccentric mother. Kate meets a flight attendant who inspires a new idea about her future.

Tara and Charmaine are rushed to the hospital in the same ambulance, where Charmaine declares her baby off limits to her crazy sister; Tara attempts to make a deal with her alters, which intrigues her Abnormal Psychology professor; Marshall, Lionel and Noah put Charmaine's empty house to some creative uses; Kate is embarrassed to confess that she backed out of going to Japan.

Tara tries to drop her Abnormal Psychology class but instead receives an intriguing pitch from her instructor, Dr. Hattaras; Charmaine and Neil find parenthood a struggle but still refuse Tara's help; Max finds himself at odds with his boss at his new job; Kate prepares for flight attendant training; Lionel catches Marshall with Noah, jeopardizing their student film project.

Tara seems to be making progress with her new contract but Dr. Hattaras discovers something disturbing in a tape from one her therapy sessions; much to the sisters' chagrin, Neil invites Tara and Charmaine's mother to visit her grandchild; Max is unhappy at his new job but can't talk to Tara about it; Kate is surprised when a handsome flyer rebuffs her flirting.

Tara motivates Max to relive his old rock band Beaverlamp. Meanwhile, a depressed Dr. Hattaras makes her take a break from their therapy sessions and Marshall and Noah interview Max for their film festival project.

A new alter comes to light that put Charmaine's new baby at risk. Soon later, Alice visits Dr. Hattaras and intrigues him in Tara's case again. Kate, Max and Marshall fly to New York where they get to meet Kate's new friend Evan and his son.

The discovery of Tara's new dangerous alter makes Dr. Hattaras and Tara consult another professional. Marshall finds out that his short film hurt his father's feelings and Charmaine connects with "chic moms," while Kate tries to make her relationship with Evan work.

Max and Marshall return home from New York to bad news on all sides. Max learns of the new alter, Bryce, but a highly medicated Tara assures him all in under control. Marshall learns that a close friend has been killed in an accident. Tara offers support, which he gladly accepts, but on the day of the funeral Bryce emerges and apparently will not go away. It's all too much for Kate and Marshall who look to strike out on their own.

When Bryce takes over, Tara's new alter threatens to destroy the whole family. When Tara's other alters disappear one by one, Max decides to fight off Bryce before it's too late for Tara.

Tara re-emerges but the task now is to repair broken family relationships, particularly with Marshall who is fed up with it all. Rather than go into a local mental health facility, she decides to follow Dr. Hatteras' advice and see a specialist in Boston. Neil and Charmaine are moving to Houston and offer to take Marshall with them. Kate receives an offer to move to St. Louis. As a new family dynamic emerges, everyone contemplates and wonders what the future may hold.