Johnny pitches an alternative way to traffic drugs to the head of a drug cartel in Mexico. Mike must cover up a horrific crime while undercover.

As the agents of Graceland strive to close out their ongoing cases and mend broken relationships, Briggs finds himself coerced into a high-risk undercover operation within the Armenian Mafia.

Briggs tries to keep control of Ari Adamian while Charlie struggles with the decision to terminate her pregnancy.

The feud between the Sarkissians and a local gang heats up; Briggs' motives are revealed; and Mike hunts for the sarin gas.

The agents struggle in the aftermath of the gang war while Briggs tracks down a loose end in order to bring Ari Adamian to justice.