When Pete discovers Violet clinging to live following a unhappy attack from a patient, he rushes her to the hospital where Addison and Naomi work together to save her life. Meanwhile, the location of Violet's baby are still unknown.
Violet is physically recovering from her unhappy attack at home, but the emotional trauma she suffers from isn't going away, despite the best efforts of Pete and her other friends to help. Meanwhile, Addison and Naomi try to mend their tension-filled relationship, as Sam and Cooper treat a father, who has allegedly attacked his family, after he is embraced by his wife.
Miranda Bailey brings a kidney transplant patient to Los Angeles, and Addison and especially Sam is pleased to see her. Addison's consequences of her emotional affair with Noah catch up with her. Sheldon and Pete finally discover who the father of Violet's baby.
Addison, Sam and Cooper treat the sick child of a homeless teen mother they met while volunteering. Violet has trouble relating to her baby when her feelings of her attack resurface during a counseling session of a rape victim who is now pregnant. Cooper's financial woes catch up with him when he's asked to help buy out Naomi's share of the practice.
Addison deals Naomi's former patients, Zoe and Amelia, whose embryos were accidentally switched, a complication that may end up jeopardizing both fetuses. Violet struggles with whether or not she can face Katie in court and testify against her. Charlotte is determined to convince Addison, Sam and Cooper to let her join Oceanside Wellness Group.
The doctors at Pacific Wellcare venture with an unexpected new hire causing Naomi to struggle with the idea of genetically designing babies. Violet makes a sudden decision to try electric shock therapy on a patient. Addison somehow finds herself alone and with a cat.
Addison and Sam go for a hike in Malibu, they come across an expecting couple trapped in their car after an accident, they then perform urgent field care. Charlotte, Cooper and Violet treat a newlywed who, on his wedding night has taken too much Viagra. Pete and Sheldon go out to a bar together and end up falling for the same girl.
Addison is thrown by the arrival of her father to Los Angeles. Cooper is arrested when he refuses to cooperate in a case involving a patient. Pete fights to keep a terminally ill patient alive long enough for him to meet his daughter.
After Addison performs a complex in utero surgery, it finally gives a common ground between her and her father. Meanwhile, Naomi and Sam have to deal with their own family crisis when they uncover the fact that their daughter is growing up way too fast, and Violet does the unthinkable.
After Dell's house is involved in a terrible explosion, it results in Betsey and Heather in the hospital, and everyone trying their best to save their lives. Meanwhile, the tension between Addison and The Captain rises even higher after her mother, Bizzy, shows up with a shocking family secret.
Mark follows Addison back to Oceanside Wellness desperate to help his pregnant daughter, while Dell and Naomi experience problems trying to raise their children under the same roof. Meanwhile, Violet and Cooper disagree on how to treat a patient, resulting in a heated argument.
Maya makes an announcement that shocks Sam and Naomi, and Naomi's response leaves Sam to pick up the pieces. Meanwhile, Pete's patient begins using a bionic arm.
Addison and Cooper lend advice to a couple who must make a difficult choice as to which daughter to save with their newborn's core blood. Meanwhile, Sam learns that Dink is going to marry Maya, and the gang plans an intervention for Naomi.
Sam has Violet help plan Maya's wedding, as Naomi becomes more distant and refuses to help. Meanwhile, tensions arise between Addison and Sam as they treat a suicidal patient, and Cooper and Pete work together to treat a girl with a mysterious bite mark.
Naomi, Addison and Pete try to save a premature baby. Cooper thinks Charlotte's new boyfriend is abusing pills.
Things get too close for comfort when Addison, Pete and Sam must come together on a complicated case involving a dad-to-be who comes down with tuberculosis and threatens the future of his new family. Meanwhile, with Violet still gone on her Costa Rican escape, Sheldon takes over helping one of her patients, Natasha, to get over her crippling fear of flying, and Naomi finds herself in a bit of a love triangle of her own.
When Addison's patient and the life of the three unborn babies she is carrying as a surrogate hang in the balance, Sam's new girlfriend, Vanessa, and Addison are sharply divided on the course of treatment. Meanwhile Cooper seeks Sheldon's help with a young patient, but their personal quarrels over Charlotte get in the way, and Naomi has a dilemma of her own between William and an unexpectedly charming Dr. Fife.
A husband's decision to pull the plug on his pregnant wife is overruled by a judge, forcing the hospital to keep her on life support until the baby is born and can survive. Naomi feels betrayed after learning of Sam and Addison's feelings for each other who turns to Dr. Fife for comfort.
When a famed neurosurgeon and her team visit St. Ambrose, Addison is surprised to see Derek's younger sister on the team; Charlotte and Cooper try to figure out how to work together.
Mark follows Addison to Oceanside Wellness in hope of helping his daughter; Naomi and Dell try to raise their children under the same roof; Cooper and Violet don't agree on how to treat a patient.
Violet files for joint custody of Lucas but Pete hires an attorney and fights back, dragging everyone at the practice into the trial.
Naomi begs Fife to use his still experimental treatment to help William's advanced ALS. Violet and Amelia treat a woman with a brain tumor, while Sheldon decides to vie for Charlotte's affections.
Addison, Amelia and Fife try to save Maya and her unborn child; Sam makes a grim discovery; Cooper makes a valiant effort with Charlotte; an unexpected death leaves everyone stunned.