Scott Bakula, in the role that made him a star, plays Sam Beckett, a scientist who's part of a time-travel experiment that "went a little... ka-ka." Unable to return to his own time, and aided only by Al (Dean Stockwell, whose rapport with Bakula is one of the series' most appealing elements), his cigar-smoking, peculiar-dressing, sex-obsessed, holographic "enabler," Sam "leaps" unpredictably from one time period and person to another, usually completely out of his element (as a pilot, a boxer, a cowboy, an English lit professor, even an elderly black man in segregated '50s Alabama) and always in a situation that needs to be "made right" before he can leap onward. Generous helpings of humor, drama, physical action, and sentimentality (this is TV, after all) keep things moving, as do references to many other classic films and genres (Driving Miss Daisy in "The Color of Truth," Casablanca in "Play it Again, Seymour," boxing in general in "The Right Hand of God") and what creator Donald Bellisario calls the occasional "kiss with history" (Sam crosses paths with the young Buddy Holly and Michael Jackson, among others). It doesn't all work, as Quantum Leap occasionally becomes too cute and facile for its own good. But that and the set's paucity of bonus material (limited to one passable featurette and brief episode intros by Bakula) are the only real shortcomings of a boxed set that will likely earn multiple spins in the DVD player. --Sam Graham