The great house stands alone, deep in the wooded reaches of the Hudson Valley. Outside, all is peace - but inside lies destruction: an almost superhuman violence, mirrored by a series of disappearances and deaths that have haunted the region. Paul Skoglund hasn't seen his eccentric, wealthy aunt in years. But her magnificent nineteenth-century hunting lodge has been ravaged, and she refuses to have anyone outside the family take on the repairs. Paul senses something amiss, but takes the job anyway. He's in no position to turn down work. Despite his brilliance, Paul hasn't held a steady job for years, partly because of his Tourette's syndrome, a strange neurological disorder that compels him to act out in bizarre and explosive ways. His icy ex-wife plans to use his condition to wrest away custody of their troubled young son. And in this otherwise uncertain world, Paul is sure of one thing: Nothing and no one is going to come between himself and Mark. As Paul and his lovely, risk-addicted girlfriend, Lia, delve into the lodge's wreckage, they can't help but wonder what dark passion - and what strength - could cause such chaos. Their search for answers takes them from the most ancient, primal human impulses to the cutting edge of biomedical research, from the science of genetics to Viking legends to forensic pathology - and across the ambiguous borderline between thought and reality. As the quickening events lead him deeper into his family's past, Paul must face the darker aspects of his own nature, and brave the possibility that in saving those he loves, he might well destroy himself.