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.

The lives of two siblings are completely upended when they discover a dead body, long buried in their parent’s basement, sending them down a rabbit hole of crime and murder.