After Violet files for joint custody of Lucas, an embittered Pete voraciously fights back by hiring a tough attorney for the trial, forcing their fellow friends and co-workers to choose sides and have their personal lives dragged onto the stand and into the public eye.

Addison's mother, Bizzy, aggressively demands her daughter do whatever it takes to save her partner from dying - including working with Dr. Rodriguez once again. Meanwhile Amelia and Pete's medical consultation is complicated when a patient's wife and his mistress disagree on the course of treatment, Charlotte and Cooper try to be intimate with each other again, and Violet considers publishing a personally-revealing book she's written.

Charlotte and Cooper look to forgive each other after revealing secrets during couples therapy, Violet seeks the forgiveness and approval of her fellow doctors after they learn her novel-in-progress will make all of their personal lives public, Sheldon treats a patient who claims to have multiple personality disorder, and Sam and Naomi team up on a case involving a pregnant teen with Down's Syndrome.

Violet's book launch party has finally arrived but Sheldon finds himself attracted to the doctor who criticized her book. A surrogate under Addison and Pete's care is caught in a complicated love triangle. Cooper and Sam must convince a family that their son's health must take a priority over his sports career.

Cooper receives the surprise of his life when a woman from his past arrives at the practice; Addison consults her patient, Jodi, who is eight and half months pregnant and suffering from severe memory loss after a traumatic car accident; and Sheldon and Violet clash when their patient, Jodi's husband, Zach, considers leaving his wife and taking the baby with him.

Addison begins in vitro fertilization treatments with Jake's help, unbeknownst to Sam, Amelia is deeply conflicted when her terminally-ill friend, Michelle, asks her assistance in her suicide, and Sam and Violet contend with a patient who refuses his anti-psychotic medication.

Amelia makes the hard decision to enter a rehab facility, and finds strength through an 18 year-old girl, as they both go through the painful detox process. Meanwhile, Cooper’s strengthening bond with his son is tested by his allegiance to a patient in need, Pete and Violet’s marriage reaches a tipping point, and Addison collapses from her rigorous fertility treatments.

Cooper struggles with whether or not to punish Mason after he catches him stealing; Pete and Violet find it hard to split time with Lucas now that they're living apart; Addison makes changes in her home life to prepare for a potential new baby; Violet and Jake work with two women and a man involved in a polyamorous triad; meanwhile Amelia returns to the practice and realizes how badly she hurt Sheldon when she was abusing drugs.

Violet steps in to the middle of a dangerous situation.

Sheldon counsels Sam's friend, Rick, an Army veteran suffering from PTSD who harbors a secret sexual trauma; Erica and Mason are involved in a car accident that forces Cooper and Charlotte to further come to grips with their future; Violet and Pete struggle to navigate life after marriage when he finds her kissing Scott; and Addison and Jake attend a medical conference they won't soon forget.

Cooper and Charlotte take Erica to Seattle Grace to meet with Derek, Lexie and Amelia regarding a very risky surgery; Scott tells Violet that he would like to take their relationship to the next level; and Addison finds herself caught in the middle of Sam and Jake's fight about a patient. Meanwhile, Sheldon warns Sam to be cautious as he deals with the return of his sister, Corinne.

Sam tries to take care of his sister, Corinne, but her mental condition makes that nearly impossible; Sheldon learns that Amelia has life-changing news; the flirtation between Addison and Jake continues, and Cooper rejects Charlotte's suggestion to seek outside help with Erica's care.

Pete and Violet enter marriage counseling to help patch up their relationship; Amelia shuts down emotionally and avoids her peers upon hearing some devastating news; Addison adjusts to the new man in her life, and Charlotte and Cooper struggle with Mason when he refuses to speak to them. Meanwhile, Violet becomes suspicious of the sister of one of her patients.

Addison, Pete and the team treat an illegal immigrant facing deportation who self-induces her pregnancy so that her child will be a U.S. citizen; Cooper and Violet work with a young girl who has gender identity disorder - and with her parents -- and Violet wants to continue therapy with Pete before they begin dating again.

When a patient's partner and father are heatedly divided on his health care, Pete makes a decision that impacts everyone, including himself; meanwhile, Jake offers strength and experience to Amelia when he suspects she's being tempted to substance abuse, Sheldon and Violet treat a family concerned about the father's new sexual appetite, and as baby Henry draws Addison and Sam closer, they struggle to define their relationship.

When Amelia goes into labor, the Seaside doctors - even those she pushed away -- come to her side as she faces the hardest decision of her life. Meanwhile, after Pete finds himself in life-changing trouble, he and Violet realize what they mean to one another, and Addison is faced with a choice.

Addison settles into her new life after making a decision between Jake and Sam; Violet fears the worst when Pete doesn't show up to his preliminary court hearing; and Charlotte swears Cooper to secrecy when she receives shocking news. Meanwhile, Amelia celebrates one year of sobriety and Sheldon rekindles a romance with his ex-wife.

The doctors join together for a celebration at Addison's house and to reminisce about the past. Meanwhile, Sheldon counsels a suicidal patient who comes forward with a shocking confession.

After hearing a patient's chilling confession, Violet turns to Sheldon for advice. Meanwhile, Addison tries to keep her grief a secret, Cooper and Charlotte adapt to their new reality and Sam confronts Sheldon about his denial.

Sheldon fears the worst when a little girl goes missing from the ER; Addison and Jake have a disagreement about one of his patients; and a new doctor joins the team at Saint Ambrose. Meanwhile, Stephanie questions Sam about his past with Addison.