Based on real-life events, this is a bombshell of a movie which centers around a young, success-driven fresh-out-of-the academy F.B.I. Agent Mark Putnam (Jack Huston) who is sent to Pikeville, a beleaguered mining town in rural Kentucky; where he is sent to as his first assignment to investigate a local chop-shop ring and various other illegal activities. He has transferred with his wife Kathy (Sophie Lowe). Once ensconced in his work, Putnam gets way too involved with a local down-on-her-luck local woman Susan Smith (Emilia Clarke) who becomes his star informant.Susan is divorced with ex-hubby Cash (Johnny Knoxville) and has 2 kids with him. She is involved in the drugs distribution business in the town as she has no other options to help her pay the bills. Cash and Susan's brother Bones (Luke Spencer Roberts) help her run night parties where customers can by and smoke drugs. At one of the parties, one customer starts fighting with Bones, who ends up shooting him. Mark teams up with local Sheriff Randy McCoy to arrest Bones at Susan's house and even uncovers a 1000 tablets of drug Percocet. Susan advises Cash to turn informant to cut a deal with Mark. Mark quickly realizes that Susan is the brains behind the operation.Mark has a knack of being able to befriend the locals. Under the guise of trying to cut a deal for Cash, Mark start seeing Susan regularly. Marks starts off slowly by offering Susan $ 10 K to snitch on a local bank robber who has hit 11 banks in 4 months. Susan snitches on the robber, who is a drifter who has been renting a room in her own apartment for the last 4 months. Susan helps Mark catch the robber and is pretty stoked that she has teamed with the FBI for something important. Sh has sex with Mark that night.Susan calls Mark's house to inquire about him, and ends up befriending Kathy and having coffee with him. Susan and Mark keep having sex with each other regularly. A few weeks later Denver Rhodes (Omar Benson Miller) walks into Mark's office and tells him about Rufus Green (Brian Lee Franklin) who runs a pot smuggling operation from Mexico and storing the pot in an abandoned coal mine he had bought. Mark gets super engrossed in this case and ignores Susan, who gets suspicious and jealous.Cash finds out that Susan is having sex with someone and locks her out, so Susan goes to stay with Kathy. That night she has sex with Mark and Kathy knows that they are cheating on her. Kathy tells Susan that she is pregnant. Susan now understands why Mark is having sex with her.. Susan goes to Rufus and warns her about the impending FBI raid. The raid is a bust as Rufus had moved everything, but he tells Mark that Susan had snitched on him this time. Mark pays Susan $6K for her help so far and cuts all ties with her.She goes to Cash to buy peace with him, and he beats her up instead & she calls Mark for help. Meanwhile Bob Singer (Kevin Dunn) is assigned as Mark's new partner in FBI. Susan testifies for the FBI in the bank robber case and is transferred to a safe house. The Susan finds that Mark is leaving town. She tells Kathy she has been having sex with Mark and she deadpans it back to her.Susan and devastated and asks for help from Bob Singer. He gives her Mark's info in the new office. She tells him she is pregnant with his child. Mark comes back to meet Susan & ends up murdering her. Back home, he tells Kathy what he did. He then goes and confesses his crime and serves 10 yrs in prison.