On the private island of Castle Fiore - surrounded by the glittering waters of Lake Garda - the illustrious Heywood family gathers begrudgingly for their son Laurence's wedding to Italian influencer Eva Bianchi. But as the ceremony begins, a blood-curdling scream brings the proceedings to a devastating halt. With the wedding guests trapped as they await the police, old secrets come to light and family rivalries threaten to bubble over. Everyone is desperate to know who the killer is? Can they be found before they strike again?