Blackwaters - "a dark river that seeks to conceal all that lies beneath its surface." The devastating blow suffered by the close-knit FBI team means the time has arrived for Kate Reid to come out of the shadow of her mentor and take the reins. A lead in the Blackwater investigation arises and Kate is the one who must follow it, but without Special Agent Nick Scarborough at her side. Turmoil within the FBI forces Nick to defend his actions and fight for his career. Meanwhile, the bodies continue to turn up in the black water rivers of northern Florida, and jurisdictional lines are blurred when the FBI's Atlanta office tries to take command. While following up on her lead, Kate soon finds herself on the brink of an important breakthrough in the investigation-one that could bring her face to face with the Blackwater Killer. Without her team by her side, how will the rookie federal agent find a way out?