It's wedding season and Viv's longtime frenemy Piper May is getting married. She convinces Viv and Scarlett to take on the job of designing the headpieces for her wedding of the year. The well-to-do bride and her entourage are delighted to have Viv and Scarlett as their famous hat designer guests, but the hat-making pair are really just looking forward to a getaway at a castle in Sussex. It is to be a weekend full of events, culminating in the big ceremony. Unfortunately, on the first night of the festivities, the groom is found murdered, and the joyous holiday becomes the stuff of nightmares as no one is allowed to leave the castle until the investigation is complete. Although Scarlett assures Harrison Wentworth, her fiancÔe, that she and Viv will stay out of harm's way, circumstances force them to step in when a secret affair between the deceased groom and a bridesmaid comes to light, and the murderer takes another life. Scarlett and Viv vow to unveil the killer's identity before the wedding adds another to its death toll.