Enhanced descriptions from Syndetics:

Bursting with the sharp intelligence and sly humor that's fast becoming his trademark, Westerfield's new novel is an utterly original take on an archetype of horror--the vampire.

Reviews provided by Syndetics

Kirkus Book Review

Both medical thriller and science fiction, this fast-paced, captivating modern vampire story is enriched with biology and history. Nineteen-year-old Cal is a hunter. He works for the Night Watch, New York City's clandestine organization to capture "peeps," "parasite positive" people infected with an ancient disease that causes vampirism. They're cannibalistic, violent and wildly strong. Cal tracks his line of contagion: an ex-girlfriend, whom he unwittingly infected, and then his progenitor, the girl who gave it to him. Yes, Cal has the parasite, but he's a carrier rather than a full-blown peep. Forced into secrecy and celibacy but possessing peep-like superhuman senses and strength, Cal simmers with adrenaline. He succeeds at his job in the dank, oppressive urban undergrounds, but he discloses secrets to an unauthorized, uninfected girl his age who becomes inextricably involved. Conspiracy issues arise; the parasite's centuries-long history holds a profound revelation. Westerfeld intersperses relevant chapters on how various real-life parasites operate in nature. Entrancing throughout--but squeamish readers beware. (afterword, bibliography) (Science fiction. YA) Copyright ©Kirkus Reviews, used with permission.