The Reacher Series is a collection of thriller novels written by author Lee Child. The series follows the character Jack Reacher, a former military policeman who travels across the United States, often finding himself embroiled in dangerous situations. Each book features a standalone story, showcasing Reacher's resourcefulness and combat skills. The first book, titled Killing Floor, was published in 1997 and introduced readers to Reacher's world. The series has gained immense popularity, leading to adaptations in film and television, including a recent series on Amazon Prime Video. The books are known for their fast-paced plots and engaging characters.