The relationship between Laurel Mercer and Emma Becker. Since Emma took Sutton's place she has grown closer to Laurel when Sutton pushed her away.
On the day that Emma and Sutton switch places, Emma goes to Sutton's house and meets Kristin, Sutton's adoptive mother. When Kristin almost drops a potted plant that she's carrying, Emma helps her with it and Laurel, who's sitting nearby, looks as though she thinks that is odd. Laurel comments that she's not wearing their grandmother's necklace and that Luke took it off to give her a hickey. She also tells her that Mads can't wait to see them in their new bikinis. Laurel sarcastically asks if she can have a ride to Mads' house and Emma says okay, which surprises Laurel. When Ted, Sutton's adoptive father, comes in and asks if anyone can take his shirts to the dry cleaners, Emma says yes and Laurel vocally expresses her surprise. When they leave the house, Emma throws Laurel the keys and tells her to drive to the dry cleaners and Mads' house. Laurel comments that she was told by Sutton to never even sit in her car but Laurel ecstatically agrees to drive. At Mads' house, Emma and Laurel hang out with Mads, Char, and Luke. Later, back at home, Emma and Laurel hang out together in Sutton's room. While Laurel paints her nails, Emma and Laurel talk about Sutton's adoption before Laurel leaves the room. The next morning, Laurel wakes Emma up and comments that everyone's going to want to see what Sutton Mercer's wearing to school. At breakfast, while Emma is eating the pancakes that Kristin has made for her, Laurel comments that pancakes we're not on Sutton's diet. At school, while walking in the parking lot, Emma and Laurel talk about what would have happened if Sutton hadn't been adopted by the Mercers, i.e. orphanages and foster care. They both notice Ethan Whitehorse being dropped off by his cop brother. Laurel wishes her good luck in her tennis match against Nisha. After the match, when Emma meets Laurel, Laurel reminds her that Emma forgot her gym bag. Later that night, at home, Emma comments that it will all be over at 10 pm. When Laurel asks what she's talking about, Emma is about to tell her when they're interrupted by Mads and Char entering the room. Sutton's two best friends convince Emma to attend Nisha's party and all four of them go together.
When Emma goes downstairs, Laurel is sitting at the counter and watches as Ted tries to dance with Emma to practice for the Father-Daughter dance later on, to which "Sutton" has apparently forgotten how to do. On the way to school, Laurel tells Emma that she's gonna skip the dance, but Emma tells her that she needs her there, much to Laurel's surprise. Laurel then shows her the footage of Emma punching Nisha in the face at the party the previous night. Laurel notices that Emma doesn't stop for coffee like they've been doing for 2 years. Emma tells her that she's skipping caffeine because she's still bothered by the break-in. Laurel tells her that whoever stole the laptop was probably looking for one of the lying games if not all of them. At school, when Emma is talking to Ethan, Laurel walks by and notices them without being seen. Arriving at the Father Daughter Dance, Laurel notices Emma and Ethan interacting. When Emma is asking Mads and Char if anyone at the dance would notice if she didn't dance, Laurel glances at Emma out of sight. During the spotlight dance, Laurel watches Emma and Ted on the dance floor. Char comments to Laurel that Emma/Sutton is different since she came back from Paris and Laurel agrees with her. She then notices Ethan watching Emma and Ted dancing. When Ted starts dancing with Char, Emma tells Laurel that she's next and that Ted really wants to dance with her. Laurel tells her that she knows how to wait her turn. Later, at the house, Laurel is watching from out of sight when Kristin shows that she found Emma's cell phone and Emma tells her that it's Char's and that maybe "Emma" is one of Char's Facebook aliases. When Ted and Kristin talk about Ethan stepping in to help Emma, Laurel comes out and tells them about Ethan and how it's like Ethan is "Sutton's" secret boyfriend.
At school, when Laurel asks if Ethan is Emma/Sutton's boyfriend, Emma tells her that Ethan freaked when Ted and Kristin found out and doesn't want anyone else to know. Laurel deviously tells her that she might not remember not to tell anyone. Emma gets that Laurel wants something from her and Laurel tells her that that's how it has always worked in their relationship: Emma/Sutton does something bad, Laurel finds out and blackmails her. Laurel then tells her about Justin, the guy she just met. Laurel describes him and Emma points him out in the hallway before walking away to let Laurel go talk to him. At lunch, Laurel tells Emma that Char called dibs on Justin. Emma mocks that concept and Laurel tells her that she/Sutton invented it. Laurel goes on to say that if she goes after Char's new crush that Char would make Laurel miserable and Emma would probably help Char do it. Emma tells her that she wouldn't do that to her sister. Laurel mocks that concept and leaves.
Laurel: "So, he's not your secret boyfriend?"
Emma: "No, uh... Ethan freaked when Mom and Dad found out. He doesn't want anyone else to know. So you have to keep it on the DL."
Laurel: "Huh. I guess I could, but how will I remember not to tell anyone?"
Emma: "You want something."
Laurel: "Uh, duh. That's how this relationship works: you do something bad, I find out about it and then blackmail you in exchange for my complete and utter silence."
Laurel Mercer: "Why would you change in the middle of the night? Okay, Sutton, this isn't funny anymore. It's like you're intentionally trying to make me think there's two of you."
Emma: "There are two of us. Laurel, I'm Emma, Sutton's twin sister, and...I'm gonna need your help."