A troubled Baltimore FBI agent becomes involved with a secret government unit assembled to hunt a group of ruthless terrorists, who may or may not be from this world, and who may or may not be involved in his wife's disappearance.
Flynn stumbles upon startling new information about his wife, which leads the ETU to a suspected human-hunter collaborator, while Flynn finds himself in an unexpected confrontation.
The ETU's discovery of the name and suspected location of a High Value Target, dredges up old memories for Jackson. Meanwhile, Flynn, Regan and Briggs attempt a daring raid on a Turkish prison.
The Hunters attempt to "reprogram" a captive Regan. While the ETU work to locate their missing agent, they deal with the possibility that there could be a mole in their ranks.