Arabella Holmes is different than other girls her age: she doesn't fit the profile of a typical lady from the 1900s. So her father, Sherlock, called in some lingering favors, and landed her a position at the Mutter Museum. The museum was Arabella's dream; she was to become a purveyor of abnormal science, or what her uncle called a "Boneseeker." Henry Watson arrives at the Mutter Museum with a double assignment—to become a finder of abnormal antiquities and to watch over and keep Arabella Holmes. It would be an easy task, if only he could get her to speak to him instead of throwing knives in his general direction. But this is no time for child's play. The two teens are assigned to a secret exploration, when the hand of a Nephilim is unearthed in upstate New York. Soon, Arabella and Henry are caught in a fight for their lives as scientific debate swirls around them. Are the bones from a Neanderthal, or are they living proof of fallen angels who supposedly mated with humans according to ancient scrolls? Sent to recover the skeleton, they discover they are the second team to have been deployed and the entire first team is dead. Now they must trust their instincts and rely on one another in order to survive and uncover the truth.