Both the East and West Bay teens attend a celebratory party where, in the two group's collision, their individual relationships are put to the test; in the meantime, Shane and Maya discover clues related to Lourdes's disappearance.
The line between East and West Bay grows more defined when the two feuding groups of teens gather on the same beach for a day in the sunlight; Carter and Sophia's relationship strain leads to a mysterious clue.
While Shane and Maya take a road trip to a marshy campground with connections to Lourdes, Ava wrestles with her new family life and memories of its former layout.
While the rest of the group attends a festive fall beach bonfire, Mal and Tatum go on their first date; following a conversation with Kylie, Carter connects a handful of intricate dots.
Ava and Jackson are revealed to each have separate, though unlikely, connections to West Bay teens; meanwhile, distracted from the mystery, Shane and Maya debate whether or not to act on their feelings for one another.
The East Bay gang decides to dig deeper into Jackson's welcoming (pilot) campfire story; Sloane and other local teens become increasingly entangled in the intricate web.
One month after Maya's move to Coastal Carolina, on the next full moon, each member of the ensemble bands together to unravel the mystery, tying Lourdes's disappearance with local legend, though more questions arise in the process.