On a stretch of highway in the Pacific Northwest known for the country's highest number of serial killers, cold cases pile up across state lines, stumping the local police. An elite FBI unit is formed, with brilliant special agent Rylie Wolf at its head-and this time she must crack the case of a string of hitchhikers who've gone missing. Are they all the work of a single killer? And can she save the next one before it's too late? ...