London, winter of 1862, Adelaide McKee, a former prostitute, arrives on the doorstep of veterinarian John Crawford, a man she met once seven years earlier. Their brief meeting produced a child who, until now, had been presumed dead. McKee has learned that the girl lives?but that her life and soul are in mortal peril from a vampiric ghost. But this is no ordinary spirit; the bloodthirsty wraith is none other than John Polidori, the onetime physician to the mad, bad, and dangerous Romantic poet Lord Byron. Both McKee and Crawford have mysterious histories with creatures like Polidori, and their child is a prize the malevolent spirit covets dearly.

Polidori is also the late uncle and supernatural muse to the poet Christina Rossetti and her brother, the painter Dante Gabriel Rossetti. When she was just fourteen years old, Christina unwittingly brought Polidori's curse upon her family. And when Polidori resurrects Dante's dead wife?turning her into a horrifying vampire?and threatens other family members, Christina and Dante agree that they must destroy their monstrous uncle and break the spell. Determined to save their daughter, McKee and Crawford join forces with the Rossettis, and soon these wildly mismatched allies are plunged into a supernatural London underworld whose existence goes beyond their wildest imaginings.