Former Marine sniper Bob Lee Swagger has entered a new phase of his life, living in exile after leaving the military. His civilian life doesn't last as long as he expects, though, with the discovery of a plot to kill the president. Former commanding officer Isaac Johnson, now a Secret Service agent, draws Swagger into the investigation by seeking his expertise for a clandestine operation to keep the commander in chief safe. The series is based on the 2007 film of the same name, which was an adaptation of Stephen Hunter's novel "Point of Impact."