The Intruders is a science fiction novel written by Michael Marshall Smith, a British author. The book follows the story of Jack Whalen, a former Los Angeles police officer, who becomes entangled in a series of mysterious events after his wife's death. As he investigates further, he discovers a secret society and their connection to alien abductions. The Intruders combines elements of mystery, suspense, and science fiction, creating a thrilling and thought-provoking read.