When Dr. Mark Baker and Nurse Kelly Atkinson are held at the mercy of a dangerous gunman, the lives of every emergency room patient are at stake. At the end of the evening three men are dead. One of them is a police officer who couldn't be saved despite Mark's best efforts. The other two are members of the feared Zeta drug cartel.

Though the standoff is over, the killing is not, because when the drug cartel loses its members, revenge is not far behind. Facing an adversary whose desires are dark and efforts are ruthless, Mark finds himself under suspicion as a killer, yet still a potential victim. When he turns to his high school sweetheart, attorney Gwen Woodruff, for help, Kelly helplessly looks on, as she hides her own feelings for the good doctor.

At the height of the conflict, three questions remain: Who is the shooter? Who will the next victim be? And can Mark prove his innocence before the gun turns on him?