On a bitter November evening, young Mary Yellan journeys across the rainswept moors to Jamaica Inn in honor of her mother's dying request. When she arrives, the warning of the coachman begins to echo in her memory, for her aunt Patience cowers before hulking Uncle Joss Merlyn. Terrified of the inn's brooding power, Mary gradually finds herself ensnared in the dark schemes being enacted behind its crumbling walls -- and tempted to love a man she dares not trust.

Kami Glass loves someone she’s never met... a boy she’s talked to in her head ever since she was born. She wasn’t silent about her imaginary friend during her childhood, and is thus a bit of an outsider in her sleepy English town of Sorry-in-the-Vale. Still, Kami hasn’t suffered too much from not fitting in. She has a best friend, runs the school newspaper, and is only occasionally caught talking to herself. Her life is in order, just the way she likes it, despite the voice in her head.

But all that changes when the Lynburns return.

The Lynburn family has owned the spectacular and sinister manor that overlooks Sorry-in-the-Vale for centuries. The mysterious twin sisters who abandoned their ancestral home a generation ago are back, along with their teenage sons, Jared and Ash, one of whom is eerily familiar to Kami. Kami is not one to shy away from the unknown—in fact, she’s determined to find answers for all the questions Sorry-in-the-Vale is suddenly posing. Who is responsible for the bloody deeds in the depths of the woods? What is her own mother hiding? And now that her imaginary friend has become a real boy, does she still love him? Does she hate him? Can she trust him?

In the Castle of the Last Towers, the things are going really Bad. Invited at a stranger's wedding, in a castle supposed to be haunted by the devil, the fallen noble Arthur de Seragens finds himself trapped in a dangerous net of insanity, betrayal and murder. While the guests are brutally murdered by an inhuman enemy, the hero discovers in terror the target may be his love interest, the beautiful Adrianna de Valois, young daughter of the dark chief of Police. Panicked and desperate, Arthur is forced to make an elusive pact with the most powerful survivors: the viscount of Vincennes, his friend, also a logician and intrigue expert; the beautiful and immoral Italian countess Giulianna Sellini, a supposed poisoner and a necromancer; Huguet de Castlenove, an ex-priest, now a dangerous killer and swordsman manipulated by his mysterious lover; the handsome, cruel and violent master of the land, Duke of Chalais; and many others, including the man who is feared by them all - Albert de Guy, from the Holy Inquisition.

But who is the mysterious assailant? A vampire? A werewolf? A serial killer? A mad incubus? Or... maybe all of them?

Violence, savagery, beauty, love and passion, logic and mystery - an inquiry in the dark.