As Moody's friendship with Pearl deepens, Elena's relationship with Mia grows increasingly strained. Unsettled by a faulty reference, Elena snoops into Mia's past while Lexie worries about her Yale admissions essay. Mia bonds with her immigrant co-worker Bebe Chow, who makes a confession with far-reaching consequences.

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.