[[folder: Fridge Brilliance ]]
* During its original run and well into syndication, I couldn't stand ''Series/QuantumLeap'' -- the "rules" governing Sam's time travel made no ''sense'' to me. "He's bouncing around from time period to time period, and he's stuck in each life until he makes things... ''nice??''" One weekend, the SciFiChannel ran a marathon of the final episodes of various shows, and I happened to catch the finale of ''QL'', which reveals that the controlling impulse behind Sam's "leaping" is [[spoiler: his own subconscious drive to make the world a better place, one life at a time]] -- and I then proceeded to catch the show five days a week for the next few months. -- Tropers/YourObedientSerpent
** The other thing that I realized (then Googled and realized to my disappointment I wasn't the first) was that, especially clear during the last season, he was realigning the "Ziggy Version" of history to match our version and that after those "major" events in modern history were lined up, he was done except for one last thing (having Beth wait for Al) which completed the alignment and therefore returned to his "Ziggy History" timeline and disappeared from our timeline (thus ending the series) -- Tropers/GaidinBDJ
* In "Star Light, Star Bright," Sam is hypnotized, and on tape, gives away the secret access code name and numbers regarding top secret information about Project Quantum Leap. An episode later, we meet an evil leaper and hologram. Clearly, someone else found the tape, accessed PQL's files, and set up their own project for personal gain!
** Mind. Blown.
** And thanks to the events of "Shock Theater" and "The Leap Back," one of the Project's handlinks is left stranded in the 1940s and unaccounted for. It won't work for another 50 years, but it's completely intact and undamaged. Between that tape and a piece of technology that could be reverse-engineered...
** That explains why the evil leaper organization does everything exactly the same with different sound effects; hologram technology, handlink, etc. Plus, Zoe was aware of just how long the window was before a successful retrieval could be performed, which means the evil organization may have improved on PQL's math.
* Throughout the series, Sam displays a reluctance to engage in any sort of relations with women, a fact that Al laments constantly. Near the end of the show's run, it is revealed that Sam [[spoiler: is married]], and suddenly his hesitation can be interpreted as a subconscious reaction to [[spoiler: the possibility of cheating on his wife]]. It also gives a more unfortunate implication to the times when he does it anyway, though.
** Donna states that she does understand, knowing that he can't remember her and is doing it to improve the lives of those involved.
** There's also the fact that when he did sleep with someone in "Trilogy", he fathered a child.
* In "The Leap Back," when Al drops the letter with the override code (and the $100) to the law firm, with instructions to deliver it on a specific date in the future (a la Back to the Future), the imaging chamber door immediately. This is because, as soon as Al dropped it in, there was no way for him to retrieve it. Hence, the "outside" time was when it was delivered, according to Gooshie, that very day.
* In The Boogieman, here's an unacknowledged, in-show visual clue: the fake Al wears a simple suit of blue and white with a silver pin on his lapel rather than his uniform or an outfit consisting of bold, clashing colours and/or garish patterns. In fact, he could have visually fit in during the time period Sam landed in.
[[folder: Fridge Horror ]]
* Occasionally, history changes to avoid a disastrous marriage. This was even the point of at least two episodes. The problem? Some of the marriages resulted in children but now, those children will [[RetGone never have a chance to live]]. Sam and Al are essentially murderers and never show any remorse about it. In one episode Al even gleefully proclaims something along the lines of "Now she won't end up having a couple of screwballs!" Suddenly, Sam and Al ''don't'' seem like such [[NiceGuy nice guys.]]
** It's not murder if you prevent someone from existing but, yes, that is pretty horrifying. There are presumably new kids who exist who live better and happier lives than the old timeline's but saying that the happiness of the parents is worth more than the ''existence'' of the children...It's a problem.
** I always thought of it like The Inquisitor from Series/RedDwarf. Instead of children being born who would do nothing with their lives, we get children who never had a chance to exist being born, children who might contribute something to society. And considering that Ziggy never reported that their children did anything (as the OP pointed out, they were a couple of screwballs), then we must assume that this was the case in the other occasions when Sam broke up a marriage.
** Plus given the existence of a seemingly benevolent God in this setting, chances are that while the kids as we know them were RetGone, they exist in some sense as different kids.
* It's been accepted by fans for years that Sam's changes to history were slowly turning his timeline into ours. The problem? His timeline was far more advanced than ours, not even counting time travel. His efforts have resulted in progress slowing down!
* It's said several times that Sam can leap anywhere in his own lifetime - but we never see him Leap ''past his original Leap.'' Which - to me at least - means that even though Sam's body is leaping around in time, he effectively died at that moment, the events of "The Leap Back" only happening post-Leap in his timeline.
* When Sam leaps into Al's younger self, hologram Al takes a ride in a jet fighter before coming to Sam. When he checks the date and time, he realizes that his girlfriend is about to die in a car accident. He teleports to the site of the crash and tries to warn her, but she can't see him (due to not being Sam) and crashes. This was probably Al's worst nightmare. First of all, his younger self only heard about the accident while older Al personally witnessed it. Second, Al tried to warn her about the crash, but failed due to her not being able to see him. There's little worse than watching someone you love die and not being able to do anything about it. This is on top of him not finding out in time due to taking the ride in the jet fighter.
* A rather major element of fridge horror actually exists because of a minor reference in another series after the show had ended. In ''Sliders'', it is implied that Maggie Beckett is in fact supposed to be Sam’s niece. What’s the problem with that? The problem is that this also implies that Maggie’s universe is Sam’s universe. Maggie’s world was destroyed. At first some of the mathematics on this doesn’t seem to work. Sam left his time originally in 1995. In “The Leap Back” he temporarily came home in 1999 (though when he changed Al’s life at the end of the series he would have prevented the events of that episode from happening anyway). However, Maggie’s world was apparently destroyed in 1997. At the same time though, 1997 was never mentioned specifically in the episode (it’s just when that episode of Sliders aired) and there was an episode of Sliders before where they “technically didn’t travel in time” because time passed more slowly there and so even though everything was exactly the same as it was in 1984 (even down to the characters calling it 1984) it was still supposedly the 90s (meaning 1997 in the Sliders’ normal time could have been 2002 in Maggie’s universe). Also, consider the fact that Sam was constantly rewriting history. He could have done something in the past which set humanity back technologically and stopped them being able to prevent the destruction of Earth. This would explain why he never made it home after the series ended. There was no home to go to.