Quantum Leap is an American science fiction television series that originally aired on NBC for five seasons, from March 1989 through May 1993. Created by Donald P. Bellisario, it starred Scott Bakula as Dr. Sam Beckett, a physicist who leaps through spacetime during an experiment in time travel, by temporarily taking the place of other people in order to correct historical mistakes. Dean Stockwell co-stars as Admiral Al Calavicci, Sams womanizing, cigar-smoking companion and best friend, who appears to him as a hologram. The series features a mix of humor, drama, romance, social commentary, and science fiction, and was named one of TV Guides "Top Cult Shows Ever." Quantum Leap follows the narrative of Dr. Sam Beckett (Scott Bakula), a brilliant scientist who has become stuck in the past as a result of a time travel experiment gone wrong, and his attempts to return to his present, the late 20th century, by altering events in the past for the better, with the aid of a hologram of his friend Admiral Al Calavicci (Dean Stockwell), monitoring him from Sams present.