Editing Quantum Leap (1989 TV series) (section)

==Premise and characters==
{{See also|List of Quantum Leap characters}}

In the very near future, [[physicist]] Dr. [[Sam Beckett]] ([[Scott Bakula]]) theorizes that time travel within one's own lifetime is possible, and obtains government support to build project "Quantum Leap". Some years later, having already spent $43 billion, the government threatens to halt funding, as apparently no progress has been made. Sam then decides to test the project accelerator himself to save the project, telling no one. He is immediately thrown back in time, but upon awakening, finds that while he physically exists in the past, he appears to everyone else as a person into whom he has "leapt", and has a partial amnesia related to his own identity.<ref name="Cerone">{{Cite news |url=https://www.latimes.com/archives/la-xpm-1990-07-15-tv-384-story.html |title='Quantum Leap' is Scott Bakula's Idea of an Actor's Dream |work=[[Los Angeles Times]] |first=Daniel |last=Cerone |date=July 15, 1990 |access-date=May 16, 2022 |archive-date=May 16, 2022 |archive-url=https://web.archive.org/web/20220516154349/https://www.latimes.com/archives/la-xpm-1990-07-15-tv-384-story.html |url-status=live }}</ref><ref name="dpbyt" /><ref name="Connor">{{Cite news |url=https://www.nytimes.com/1989/03/30/arts/review-television-comeback-for-wimps-in-new-series.html |title=Review/Television; Comeback for Wimps in New Series |work=[[The New York Times]] |first=John J. |last=Connor |date=March 30, 1989 |access-date=February 12, 2017 |archive-date=November 8, 2016 |archive-url=https://web.archive.org/web/20161108030705/http://www.nytimes.com/1989/03/30/arts/review-television-comeback-for-wimps-in-new-series.html |url-status=live }}</ref><ref name="Chunovic, Louis 1995">Chunovic, Louis, ''The Complete Quantum Leap Book'', Citadel Press (1995)</ref>

A hologram of his best friend, [[United States Navy]] [[Rear admiral (United States)#Rear admiral|Rear Admiral]] [[Al Calavicci]] ([[Dean Stockwell]]), appears, visible and audible only to Sam, who explains to Dr. Beckett that it appears he must fix something that "went wrong" in time. Al is aided by project Quantum Leap’s artificially intelligent supercomputer, nicknamed Ziggy, who is described as a "[[quantum computing|parallel hybrid computer]] with a massive ego". Despite successfully changing the past in episode 1, Sam continues to leap, seemingly guided by what is eventually described as “an unknown force" that wants him to put right events in the past that once went wrong, for reasons unknown. Thence forth, Dr. Samuel Beckett leaps from life to life and time to time, attempting to "put right what once went wrong and hoping each time that his next leap will be the leap home".<ref name="Cerone"/><ref name="dpbyt" /><ref name="Connor"/><ref name="Chunovic, Louis 1995"/>

Sam has six doctoral degrees, a black belt in [[kung fu]], a photographic memory, and near-virtuosic musical talent, allowing him to easily slip into the shoes of almost anyone in the past. The somewhat bookish and naive Sam is contrasted by Al, who is, among other things, a [[promiscuity|womanizing]], [[cigar]]-smoking, five-time divorcé who spent his early years in an [[orphanage]], was active in the [[civil rights movement]], and was even a [[prisoner of war]] in [[Vietnam War|Vietnam]].

Sam and Al are the only characters to appear in every episode. The supporting characters of each episode are the friends, family, and acquaintances of the person Sam has leapt into. With a few exceptions, such as two-part or sequential episodes, these characters appear only once, though several actors have played multiple characters. Occasionally, Sam runs into real-life historical figures such as [[Buddy Holly]], [[Michael Jackson]], [[Donald Trump]], [[Marilyn Monroe]], and [[Dr. Ruth Westheimer|Ruth Westheimer]], the last of whom played herself.

The other members of the Quantum Leap team, though mentioned often, appear in only a handful of episodes. They include [[software engineering|head programmer]] Irving "Gooshie" Gushman ([[Dennis Wolfberg]]), [[psychiatry|psychiatrist]] Dr. Verbena Beeks (Candy Ann Brown), [[biomedical scientist|medical technician]] (and Al's lover) Tina Martinez ([[Gigi Rice]]), and Sam's wife, Dr. Donna Eleese ([[Teri Hatcher]]/[[Mimi Kuzyk]]), the project's director in his absence. The latter does not exist as Sam’s wife until Dr. Beckett changes history.