One happy couple. Two divided families. A wedding party to die for. 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?