On an island off the windswept Irish coast, guests gather for the wedding of the year - the marriage of Jules Keegan and Will Slater. Old friends. Past grudges. Happy families. Hidden jealousies. Thirteen guests. One body. The wedding cake has barely been cut when one of the guests is found dead. And as a storm unleashes its fury on the island, everyone is trapped. All have a secret. All have a motive. One guest won't leave this wedding alive.