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.

The Flipside Formal offers Emma the chance to try and trap Rebecca and Sutton in a lie, but she needs Ethan's help to pull it off. Laurel struggles with where her loyalties lie, while Kristin makes a troubling discovery that has more significance than she realizes. Jordan continues to waffle between Laurel and Mads, and Theresa's defense of Alec threatens to drive a wedge between her and Dan. Meanwhile, Rebecca and Ted, and Alec and Kristin, each reminisce about old times.