From Alice Hemming, the bestselling author of The Dark Unicorn series, comes a brand-new story filled with vampires and a mystery only one girl can solve. The town of Valesti was once rumoured to be the home to a family of twelve vampires who wreaked havoc on the towns people. Until, that is, hunters came to kill them all. At least, they thought they'd killed them all . . . Years later, the rumours are mostly forgotten but some persist - especially those around Castle Bezna , where a mysterious countess lives.

Over the years, the countess has enlisted village girls to be her companions, but none of the girls have returned. But when a girl named Vivi decides that the promise of an education and boarding is too great an opportunity to turn down, she packs up her belongings and starts work in the dusty old castle. But soon Vivi starts to wonder if the legend of the thirteenth vampire could be true. Can she prove the vampires existence, or will she join the long list of girls never to return from Castle Bezna . . . ?