Addison's brother makes a surprise visit, causing trouble for her, Sam and Naomi; Meg comes back to try and make it work with Pete; a patient accused of a crime angers Violet and Dell.

Violet discovers she's pregnant, but is unsure which of the men in her life is the father of the child. Addison deals with her guilt for kissing Wyatt. Meanwhile, Charlotte proposes to Cooper.

Addison's brother, Archer, moves to Los Angeles to work at Pacific Wellcare; Cooper encourages Violet to discuss her pregnancy with Pete and Sheldon.

When Archer has a severe seizure, Addison and Naomi use every resource possible to determine the cause and a cure; Violet tells Pete and Sheldon that she is pregnant; Cooper cares for an abandoned patient.

Derek asks Addison to work with his pregnant patient while Archer recuperates from surgery; Bailey and Naomi work together to find the cause of Sam's sudden asthma attack; Cooper, Violet and Pete treat a woman with postpartum depression.

Addison suspects that Archer is up to his old tricks; a patient's child is born with male and female reproductive organs; Violet and Sheldon co-lead a therapy group for couples.