Brain Twister  (Paperback, Randall Garrett, Laurence M. Janifer)

The story follows the protagonist, Walter J. "Fitz" Fitzpatrick, a secret agent working for the PSI Division of the Federal Security Agency. Fitz is tasked with investigating a mysterious case involving a man who claims to be from another world and possesses advanced knowledge and abilities. As Fitz delves deeper into the case, he discovers a complex web of intrigue, espionage, and interstellar conflict. "Brain Twister" combines elements of science fiction, mystery, and espionage thriller, with a focus on mind-bending puzzles and unexpected plot twists. The novel is known for its engaging narrative, well-developed characters, and imaginative world-building. Overall, "Brain Twister" is a compelling and entertaining read that will appeal to fans of science fiction and mystery alike.