Winter 1888. At an asylum in the English countryside, a man suspected of being Jack the Ripper kills an orderly and flees into the rain-soaked night. His distraught keepers summon the Lady Vivienne Cumberland-who's interviewed their patient and isn't sure he's a man at all. An enigmatic woman who guards her own secrets closely, Lady Vivienne knows a creature from the underworld when she sees one. And he's the most dangerous she's ever encountered...