Hungerstone by Kat Dunn

Lenore has been married for ten years to Henry, a steel magnate, and the marriage has gone sour. Henry takes them from London to the remote moorlands for a hunting party, and a carriage accident brings the mysterious Carmilla into their household: pale and weak by day, vibrant by night, she awakens something in Lenore. As girls in the nearby villages fall ill with a consuming hunger and the hunt draws near, Lenore unravels, torn between winning back her husband and her desire for Carmilla, and uncovers a darkness in her own home that puts her in danger. A feminist reworking of Sheridan Le Fanu's Carmilla.