When a young doctor goes for his daily run in New York City 's Central Park and doesn't come back, NYPD detective April Woo is convinced that he's still alive. Trusting her usually solid instincts, she goes outside her jurisdiction and orders a massive search using the city's best K-9 tracking unit. But it isn't until a witness in the case is brutally murdered that April's hunch is taken seriously – by her superiors, by the mayor and by the already frenzied press. Only now, it just might be too late to beat the clock and stop an out-of-control killer on the most bizarre and disturbing crime spree the city has ever seen.