One year after a mysterious accident left her with amnesia, 17-year-old Cadence returns to Beechwood, an island off Martha's Vineyard, seeking answers. As three generations of the distinguished Sinclair family gather at their private summer utopia, no one will talk about the accident – neither her childhood friends "The Liars" nor her first love Gat, forcing her to uncover the truth herself.
| Actor | Role |
|---|---|
 Emily Alyn LindCadence Sinclair | Cadence Sinclair |
 Shubham MaheshwariGat | Gat |
 Joseph ZadaJohnny Sinclair | Johnny Sinclair |
 Esther-Rose McGregorMirren Sinclair | Mirren Sinclair |
 Dempsey BrykEbon | Ebon |
 David MorseHarris Sinclair | Harris Sinclair |
 Caitlin FitzGeraldPenny Sinclair | Penny Sinclair |
 Candice KingBess Sinclair | Bess Sinclair |
 Mamie GummerCarrie Sinclair | Carrie Sinclair |
 Rahul KohliEd | Ed |
 Wendy CrewsonTipper Sinclair | Tipper Sinclair |
 Brady DroulisWill Dennis | Will Dennis |
 Emerson MacNeilBonnie Sheffield | Bonnie Sheffield |
 Manaia WallLiberty Sheffield | Liberty Sheffield |
 Dylan BruceBrody Sheffield | Brody Sheffield |
| LLeandro ViguerasYoung Gat | Young Gat |
 Raewynn MartelYoung Cadence | Young Cadence |