While helping Eric (guest star Sommer Carbuccia) deal with his PTSD, Archie (KJ Apa) is forced to confront his own past trauma in the Army. To find the Lonely Highway killer, Betty (Lili Reinhart) and Tabitha (Erinn Westbrook) come up with a way to lure truckers to Pop's. Cheryl (Madelaine Petsch) extends an invitation to Kevin (Casey Cott) and Veronica (Camila Mendes) gives Reggie (Charles Melton) a shot to prove her wrong.