When a high school chemistry teacher and his family are kidnapped, DCO takes the case because the teacher is a former chemical weapons engineer for the Russian Army, hidden by the CIA in the Witness Protection Program. Martin, Crystal and Troy Buchannan go undercover to infiltrate the Chechen mob, rescue the family and stop the production of the deadly gas.
Martin assumes the legend of Dante Auerbach, an international arms dealer known as the 'Lord of War', in order to track the sale of VX gas, and rescue kidnapped chemist, Richard Hubbard. He makes contact with beautiful arms dealer Ana Paulanos, the right hand of a mysterious Chechen mobster, 'The Colonel'.
Martin is put on leave after the confrontation with The Colonel. He begins looking into his own past and The Stranger's assertion that 'Martin Odum' is a legend. This off-book investigation leads him to a mysterious smuggler in Houston who may have the answers he needs. Martin assumes the legend of a Southern outlaw in order to infiltrate the smuggling operation and get close to Dobson.
Martin takes Kyle Dobson into custody in the aftermath of a shoot-out with the smuggling crew. But when Dobson is wounded, Martin is forced to get him medical attention at a Houston Hospital. Dobson's mysterious employer, The Verax Corporation, sends a team of professional hitmen to retrieve Dobson, forcing Martin to take his prisoner on the run in a frantic escape back to Los Angeles.
Martin Odum is a fugitive, hiding out in present day London and wanted by the FBI for a crime he did not commit. He can't remember his life prior to an injury he suffered in the Iraq War, so he's searching for clues about his true identity with the help of CIA agent Nina Brenner. Meanwhile, in 2001, FBI agent Curtis Ballard and his Czech Police partner, Gabi Miskova, launch an investigation into a Russian gangster named Dimitry.
In present day London, Martin is finally able to make contact with Ilyana Crawford, a woman who may be linked to his past. Unable to get answers from her, he turns to her teenage daughter, Kate, who is in search of her own identity. In 2001 Prague, Dmitry is on a mission to locate a wanted war criminal believed to be connected to the Chechen gangsters. But Dimitry's handler is concerned that his infiltration techniques may be crossing the line.
It's a race against time as Martin searches for Kate in Paris. He's convinced the peaceful protest she's attending may turn violent at the hands of her friend Ifti, a boy with radical beliefs. In 2001 Prague, Dmitry discovers that the key to getting close to Doku Zakayev may not be his brother Tamir, but instead Doku's wife, Ilyana. In 1991 Lithuania, a younger Ballard is involved in an incident that will affect the rest of his life.