Party preparations for Mirabelle McCullough's first birthday are underway as Mia helps Bebe search for her daughter. To Pearl's dismay, Moody tries to take their relationship to the next level at the Homecoming dance while Izzy sends a message to April. Mia's discovery at Mirabelle's birthday threatens her newfound friendship with Elena.

Moody is envious of Pearl's friendship with Lexie, as Lexie enjoys her newly sexually-active status with Brian. Inspired by Lexie, Pearl explores her budding sexuality and sets her sights on Trip. Mia and Elena find themselves at odds over Mirabelle/May Ling, which ends in an epic showdown and launches a custody battle.

Bill Richardson has his hands full representing the McCullough's in the custody case, much to Izzy's dismay. Lexie finds out upsetting news and turns to Pearl for help. Meanwhile, Elena – feeling as though this whole custody battle is her fault – goes to New York to search for clues about Mia's past and enlists the help of an old acquaintance.