In the summer of 1984, the police search the Knocknaree woods after three children are reported missing. Adam Ryan is the only one found, shoes filled with blood and no recollection of what happened. Twenty years later, Adam Ryan goes by Rob Ryan and works as a detective for the Dublin Murder Squad. His past is his best kept secret. When Rob and his partner Cassie are assigned to investigate the murder of a 12-year-old girl in the same Knocknaree woods, memories resurface, relationships change, and the minds plays tricks.

An Island off the coast of Ireland, recently purchased and renovated, is the setting for an elite wedding. The guests arrive, boating across the choppy sea. A storm is in the air. This is supposed to be the happiest weekend of their lives, but it is anything but. As the weekend progresses, guests reveal more about their pasts. Everyone is connected, and no one has forgotten what's happened. The wedding is perfectly planned, not a thing could go wrong. Until someone dies, that is.