Seventeen-year-old Marie mixes perfumes to sell on market day in her small eighteenth-century French town, to save money for a dowry for her sister, Ama. But her perfumes are more than sweet scents in cheap, cut-glass bottles: A certain few are laced with death. Marie laces the perfume delicately - not with poison but with a hint of honeysuckle that she's trained her sister to respond to. Marie marks her victim, and Ama attacks. But she doesn't attack as a girl. She kills as a beast. Marking Ama's victims controls the damage and helps keep the suspicion at bay. But when a young, unmarked boy turns up dead one morning, Marie is forced to acknowledge she might be losing control of Ama. And is she can't control her, she'll have to cure her. She knows the only place she'll find the cure is in the mansion where Ama was cursed in the first place, the home of Lord Sebastiian LeClaire. But once she gets into the mansion, she discovers dark secrets hidden away -- secrets of the curse, of Lord Sebastian...and of herself.