As December casts its chilly eye over Derbyshire towns bedecked in festive cheer, the skeletal remains of a forgotten man lie hidden in the cellar of the historic Black Swan pub. The glow of a million fairy lights and the hauntingly familiar melodies of Christmas carols fill the vast halls of Charleton House, but when a group of volunteers fall ill after drinking mulled wine laced with poisonous berries, Catering Manager and part-time sleuth Sophie Lockwood wonders who's failing to embrace the goodwill of the season. Despite DS Harnby warning her to leave the mystery of the mulled wine to the police, Sophie can't resist making a few enquiries alongside her quest to piece together the tragic sequence of events that led to the century-old skeleton being abandoned in the pub cellar. Then an anonymous gift of poisoned cookies is left on her desk, and her delve into the past threatens to uncover a secret that will shock her well-respected employers, the Duke and Duchess of Ravensbury, to the core. Has Sophie's sleuthing finally gone too far? Raise a glass of Christmas cheer as Sophie faces an unwelcome blast from the past, while her best friend Mark's historical knowledge proves invaluable, and self-appointed sidekick Joyce makes her own unique and hilarious contribution. With these three around, this festive adventure can only come to a delightfully heart-warming close.