Galveston has a killer on the loose who is targeting law enforcement officials and using a fatal injection of snake venom to take them down. Authorities suspect the Veneno gang is behind it, and FBI Agents Leah Riesel and Jon Colbert join forces to track down those responsible. Their best lead is an eyewitness who claims to have seen a young man dumping the third body on a church doorstep. When their suspect goes into hiding, those closest to him are reluctant to share anything that might help the investigators.
As Leah and Jon examine the connections among the victims and dig deeper into motives, they discover appearances might be deceiving. Someone is eager to keep secrets hidden, and Leah and Jon must face their greatest fears in order to stop the next fatal strike.