The picture-perfect lives of the Richardson family are upended by the mysterious arrival of artist Mia Warren and her daughter Pearl in Shaker Heights, OH – an idyllic town founded on the utopian principles of harmony and order. Egged on by her guilty conscious, do-gooder Elena Richardson rents to the mother-daughter duo, irrevocably intertwining the fates of the two families.

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.

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.

In 1981, a young Mia begins studying at the School of Visual Arts in New York City, where she meets the captivating photographer Pauline Hawthorne. Struggling to pay her tuition, Mia makes a decision that will change the course of her entire life. Meanwhile, in Ohio, a young Elena questions past choices as she adjusts to life with a fourth child.

Mia, Bebe, and lawyer Ed Lan prepare their case against the McCulloughs. Izzy grows closer to Mia over a shared experience while her relationship with Elena reaches a boiling point. Bill and Elena's marriage is tested. Trip and Pearl continue to explore their relationship while Lexie and Brian consider ending theirs.

Elena's bombshell reveal to Pearl threatens to forever damage Pearl's relationship with her mother. Moody feels betrayed when he discovers Trip and Pearl's secret. And the jury's divisive verdict triggers a series of catastrophic events, which leads three of our characters to leave Shaker Heights for good.