On a beautiful weekend in May, Grace Doran and her friend Sarah travel to Castle Cove to stay in a luxurious summerhouse, The World's End, with Sarah's boyfriend and some of his friends.

After a night of partying and sizzling temptations, they hire a boat and sail to a nearby island. Five go out, only four return.

One year later, Private Investigator Lana Bowen journeys to Castle Cove. Haunted by a traumatic event in her past, and tormented with panic attacks, she fights her own demons as she tries to piece together what happened on the island. The further she delves, the more she uncovers – a web of deceit, betrayal and a sinister undercurrent.