"Reacher" is a popular action-thriller series based on the character Jack Reacher, created by author Lee Child. The series follows Reacher, a former military policeman who travels across the United States, often finding himself in dangerous situations where he uses his skills to solve problems and fight injustice. The character has been adapted into various media, including films and a television series. The most recent adaptation is the Amazon Prime Video series, which features Alan Ritchson in the lead role. The stories typically involve crime, mystery, and Reacher's unique ability to navigate complex situations.