Ryder Creed's priority is to keep his scent dogs safe. In the dark there are threats that are impossible to see or predict. Ever since his Marine K9 unit searched for IEDs in Afghanistan, he's avoided nighttime searches. But when a boy goes missing in a remote area of the Florida Panhandle, Creed has to put aside his fears and navigate the risks his dogs will face after dark. In the middle of the night, FBI Agent Maggie O'Dell is called to a crime scene in D.C. The M.O. matches another murder from before in the same area. Maggie and her team at Quantico believe this killer struck in other cities and is targeting homeless men. After another attack leaves a colleague hanging on for life, Maggie grabs the only tip they have. She's determined to track this killer herself as he flees D.C. and leads her hundreds of miles to a place she never expected. When Sheriff Norwich enlists Ryder's help to find a missing boy, it's personal. The young boy is someone Ryder and his crew know. The search will lead them deep into the forest and after dark. The paths of Ryder's missing boy and Maggie's killer are about to collide.