After revealing Sutton's real relationship with Ethan, the Mercers insist she invite him over for dinner. Hesitant because of his obvious feelings for Emma, Ethan obliges, only to have the dinner cut short by a disturbing visit from Dan. As Emma and Ethan struggle to keep order in Arizona, Sutton and Thayer discover shocking revelations in Los Angeles pertaining to the search for the girls' birth mother. Although the outcome may not turn out to be what Sutton had hoped for, it does lead her to wonder what everyone around her has been hiding for all these years. Will Sutton be able to find the answer about why she and Emma were separated, or will her curiosity put her and her loved ones' lives in danger?

Meanwhile, Laurel falls for a new guy in school hoping she will finally have something of her own, as opposed to always being in Sutton's shadow. Unfortunately her wishful thinking is cut short when Char calls dibs on the one Laurel did not want to share.

After waking up from a terrifying nightmare, Emma learns that Sutton has been suffering from the exact same dream for years. Sutton locates the house which Emma shared with their long-lost mother. Meanwhile, as Emma tries to convince Ted that Ethan is innocent, she hits a nerve. She believes Ted is feeling guilty and knows more than he is willing to share.

Emma is forced to go up against Neesha for Homecoming queen which causes problems with her and Sutton. Sutton and Emma both try to find more info on their mom while Alec and Ted try to hide it.

Sutton is furious when she learns that Emma and Ethan kissed. Sutton and Emma continue to find more info about their mom. Meanwhile, Laurel becomes suspicious when Justin keeps breaking dates. Also, Mads learns Edwardo is moving and Char goes on a date with a boy she found in her pool.

On the night of the country club’s Black and White Ball for junior members, Emma finds herself on the outside looking in, and Ethan must put up a façade in order to protect her. Although their loyalty to each other is strong, the jealousy and lies start to take their toll. Can Emma and Ethan look past their doubts and mend the wedge forming between them?

Meanwhile, Laurel and Ted are both left reeling after they discover the motive behind Justin’s actions. And Rebecca and Mads counsel each other on matters of the heart.

Ethan insists on helping Emma get the answers she's looking for about her twin sister. So when a tattoo sparks a memory about Sutton, Ethan pursues an explanation. But the information proves costly when Ethan heads into a situation that quickly gets out of control.

Meanwhile, Mads sneaks off to see Ryan, and Laurel continues to see Justin against her parents' wishes.

When Ethan is implicated in a serious crime, he and Sutton leave town and hide out with his father, Ben, on the reservation where he grew up. A burgeoning tension between father and son has Sutton playing mediator, but, despite the awkwardness, she appreciates seeing a side of Ethan that she did not know when they were together.

Meanwhile, Emma is left to deal with the aftermath of Ethan’s situation when she must pretend to be witness to a scene where she was not present.

Alec is in jail after his arrest for murder, but he still manages to unnerve Emma. Rebecca and Sutton formulate plans for the Mercer family.

Sutton steps up her plans to win back Ethan, and makes a point to let Emma know her intentions. Feeling left out of Emma and Thayer's growing closeness, Mads visits her father in prison and shocks Emma with a family revelation. Dan continues his investigation into Derek's murder, regardless of Alec's arrest, and Jordan starts at his new school and tries to get close to Laurel.

Emma and Thayer further their investigation into the twins' birth mother and what Sutton may know about her. Laurel begins to suspect that something is not right with her sister and makes everyone nervous when she starts asking questions. Using ammunition provided by Rebecca, Sutton lashes out at Kristin during what is supposed to be a peaceful Mercer family dinner.

Ethan's confession to Dan threatens to shatter the brothers' relationship forever. Sutton receives a mysterious phone call that may provide some valuable information. Emma's feelings for Thayer are tested when she finds herself in close quarters with Ethan. And someone else comes face to face with Emma and Sutton.