When ongoing investigations clash, Briggs and Mike seize the opportunity to tilt rival gangs against each other while Mike learns that undercover life comes with many moral complications.
Briggs calls on the house to help Lauren with her case against the Russian Mafia and Charlie gets into some hot water when her C.I. proves unreliable during a dangerous drug deal.
Despite Briggs' hesitations, Mike gets recruited by a Nigerian drug lord to teach gang members how to shoot well, while Paige recruits Jakes and Tuturro to go undercover with a flirtatious and dangerous female pot farmer.
While Mike gets deeper into Bello's organization by trying to convince him to hire him as his bodyguard, Briggs and Charlie resume their former identities as a sexually-charged couple to get intel on a mysterious drug supplier called Odin from a drug dealer names Quinn.
Dark secrets are revealed when Charlie decides to tell the house that she used heroin undercover. Briggs is finally forced to come clean to Mike, but just as Mike thinks his investigation is coming to a close, Briggs has a darker secret up his sleeve.
The newly formed Briggs-Bello alliance is tested when members of the Caza Cartel head north with a deadly ultimatum. During the aftermath, Mike is forced to push his own limits for the good of the case.
Bello's last strike to the Caza Cartel sets a war in motion that Graceland now needs to stop. While on her hunt for Odin, Charlie meets an unusual ally and Briggs comes face to face with the past.
Tempers flare and relationships are pushed to the brink when Charlie discovers a secret about Briggs and begins working with a Federale to find the truth. Mike discovers that Juan is missing and that the FBI has a suspect: Paul Briggs.
Looking for the truth about Juan's disappearance, Briggs and Mike play a dangerous game of cat and mouse- forcing Briggs to make a major decision about his future.
In this season finale, the infamous Caza enforcer Jangles takes a member of Graceland hostage and the house must come together in order to save one of their own from a sadistic killer.
