Georgie, Lissa and Bronwyn have been best friends since they met on their college swimming team. Now Lissa is dead - drowned off the coast of the remote island where her second husband owns a luxury resort. But could a star open-water swimmer really have drowned? Or is something more sinister going on? Brought together for Lissa's memorial, Georgie, Bron, Lissa's grieving husband and their friends find themselves questioning the circumstances around Lissa's death - and each other. As the weather turns ominous, trapping the guests on the island, it slowly dawns on them that Lissa's death was only the beginning. Nobody knows who they can trust. Or if they'll make it off the island alive...