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.

As Erica's condition worsens, Cooper and Charlotte try to prepare Mason, who's in denial, for the worst; Violet and Pete find that they still have feelings for each other; Addison encourages Amelia to embrace her impending motherhood; and Sheldon and Jake treat a pregnant woman who was jailed for killing her other two children.

In this Addison-centric episode, her role as a parent is challenged when Henry's biological mother reappears and asks to be more involved in her young son's life. Meanwhile Addison reconnects with her mentor, who shares a very painful secret.

Upon hearing that he must meet with Henry's social worker during a home visit, Jake fears that an incident in his past will come to light. Meanwhile, Addison becomes skeptical of Jake's needy patient and James continues to pursue Amelia.

Addison attends Henry’s court date and realizes that the judge still has some concerns about Jake’s past, Sheldon introduces Miranda to his friends, and Cooper’s efforts to secure a dream house are put on hold when Charlotte goes into labor.