To keep things calm at home, Laurel decides to pretend that she and Justin are over, while continuing to see him in secret. At an open mic event with Justin, Laurel meets a musician named Baz, who asks her to join his band. Back at the cabin, Emma bonds with Thayer over video games, telling him about her childhood. Meanwhile, Alec tries to help Rebecca attain a membership at the club, getting her an interview.
Emma, Sutton, Thayer and Ethan put their heads together to figure out who caused Sutton to drive the car into the lake. After seeing Derek's snake tattoo, they link him to "the snake" that Annie Hobbs described on the man she saw that night. Ethan roughs Derek up at school to try to get him to confess, but he swears that he doesn't know anything. After school, they go to Derek's house and learn from his mom that Ethan's brother, Dan, drove Derek home the night of Sutton's birthday...and that he was soaking wet. While Sutton and Emma switch back, Ethan confronts Dan about what happened that night. Feeling guilty, Dan asks Alec to reopen the case by bringing Derek in for questioning, but Alec refuses.
Sutton agreed to help Mads sneak out on a date with Ryan by telling her dad that they were studying together. But Emma doesn't know that she's covering for Mads and calls Alec to find out why Mads never showed. A worried Alec cancels his plans with Rebecca, but she drops by to make him dinner and keep him company.
Meanwhile, Ethan and the real Sutton track down Derek at an auto shop. When Sutton asks Derek why he tried to kill her, he plays dumb before trying to hit Ethan with a tire iron. Ethan dodges his attack and punches Derek in the face, but a car pulls up and they run for it. On their way back to the cabin, Ethan and Sutton get pulled over for a broken tail light, but the officer recognizes Ethan and lets them go.
The next morning, the police find Derek dead at the shop. The officer, who pulled Ethan over, tells Dan that he saw Ethan's bruised hand and that he has to report him as a suspect. Dan gives Ethan some money and tells him that he needs to run away, or else he will be blamed for the murder. Ethan takes Sutton to school to switch back with Emma before he leaves, but the cops show up and grab her first.
At a jewelry store, a saleswoman helps Rebecca pick out an engagement ring. When she asks Rebecca if he's popped the question, Rebecca says, "Not yet, but it's only a matter of time."