Lawyer Thea has just won the biggest case of her professional life when she receives a mysterious invitation - and finds herself on a jet, being whisked off to a private Caribbean island. Except this is no holiday. Thea's fellow guests represent the world's richest individuals and, on arrival, each is challenged to make The Pledge - to give half their fortunes to fight climate change. But underneath the billionaire lifestyle is a game of survival of the fittest. And, by the morning, their manipulative and misguided host is dead. Thea must navigate secrets, lies and scandals as the group's suspicions turn on her. Now, she's not just relying on her courtroom wiles to win a case; she's fighting for her life. Because, when another guest dies, it's clear she's not just stranded on the island - she's trapped with a killer ...