Unlike the other two previously released features that share this premise, The Marksman is based not on a book, but on an original script by Chris Charles, Danny Kravitz, and Robert Lorenz, which based its story on an Arizona rancher named Jim Hanson (Neeson ) focused. . His property, which lives on the south side of the state, is partially delimited by the fence between the United States and Mexico. As a result, he has regular contact with illegal immigrants. In most cases, he quickly calls his daughter-in-law Sarah (Katheryn Winnick) who is a member of the US Border Patrol. However, circumstances change when he meets a mother, Rosa (Teresa Ruiz), and her son Miguel (Jacob Perez), who is desperately running away from a drug cartel.