Living in nineteenth century England means Emma Crawford's future is already mapped out for her: she will marry the local rector, settle down and have children. Emma, however, is a dreamer, preferring to escape into the poetry of the infamous Lord Vairnruth. Her favourite work is his erotically-charged masterpiece, The Water Nymph, a folklore-inspired tale of a lake-dwelling seductress who devours mens' souls.

When Emma discovers her new fiancé is an old friend of Vairnruth's, she sees an opportunity to escape her mundane existence. An invitation to Vairnruth's birthday weekend opens up a new world of decadence and debauchery—not to mention an introduction to his Lordship's free-spirited sister, Louisa. But as Emma is drawn deeper into the siblings' sensual games, she begins to suspect that something supernatural lurks in the mansion's lake. Could it be that The Water Nymph is more than just a fairytale?