On the private island of Castello Fiore - surrounded by the glittering waters of Lake Garda - the illustrious Heywood family gathers 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 is the killer? And can they be found before they strike again?