?Science writing as detective story at its best.? ?Jennifer Ouellette, Scientific AmericanA New York Times Notable Book of the Year, a Scientific American Best Book of the Year, and a Finalist for the National Book Critics Circle Award.Ebola, SARS, Hendra, AIDS, and countless other deadly viruses all have one thing in common: the bugs that transmit these diseases all originate in wild animals and pass to humans by a process called spillover.