Addison disagrees with Naomi on the designer baby methods she did for Molly and Eric Madison in order to save their 7 year old son. But when 6-month pregnant Molly decides to bring on her labor as her son's condition deteriorates it is up to Addison to save the baby and reluctantly donate the core blood to the baby's brother. Meanwhile, Cooper and Charlotte continue their behind closed doors affair and it causes him to abandon his usual annual holiday with Violet. Elsewhere, Pete asks Addison out just as Kevin comes back on the scene, Dell quits and Naomi tells Addison that the practice is in trouble which causes Sam to relieve her of administrative duties.

Sam and Naomi realize they can be friends, while Cooper encourages Violet to talk to Pete and Sheldon about her pregnancy. Addison's brother moves to LA and begins working up on the fourth floor for Charlotte, who continues to rebuff Cooper's advances towards mending their relationship. A patient for Addison is experiencing some stroke-like symptoms, while pregnant.

Violet's emotional reaction to her attack has all her friends on standby alert, afraid she'll freak out. Addison makes no effort to ease tensions between her and Naomi, while the practice tries to deal with a woman they feel is covering up something when her husband shows up at the hospital with a stab wound.

Addison and Sam's relationship is strained when they disagree over the treatment and safety of a comatose patient who has become pregnant, while Pete and Charlotte are faced with the ethical dilemma of revealing the HIV status of a patient who has been in a serious auto accident. Violet crosses some boundaries with Pete's family as she gets caught up in the fray of Lucas's first Halloween.

Charlotte runs the hospital from her bed; Mason starts acting out.