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.

Desperate to help his pregnant daughter, Mark (Eric Dane) follows Addison back to Oceanside Wellness, Dell and Naomi struggle to raise their children under the same roof, and Violet and Cooper heatedly disagree on how to treat a patient on.

Charlotte's painful memories of a horrible tragedy are triggered as Amelia continues her downward spiral; Addison takes one step closer to motherhood when she finally chooses a sperm donor; Cooper faces a difficult decision when he realizes his patient's parents have been drugging their son in an effort to control his supposed ADHD; and Pete's trust issues prevent him from repairing his fragile relationship with Violet.