Abby's mother decides to stay in Chicago, causing Abby even more trouble. When Weaver accepts Dr. Legaspi's dinner invitation, Weaver learns that she has misunderstood Legaspi's intentions. Carter tries to find a drug addict who has left the hospital against medical advice. Chen's mother visits the ER and invites her to dinner, even though she is surprised by Chen's pregnancy, and speechless when Chen tells her that the father is black. Greene discovers that he has a brain tumor. Corday is sued for malpractice by Mr. Patterson, the patient whose surgery she rushed so she could start her vacation, and later discovers that she's pregnant. Carter saves Abby after an explosion in exam room three.