7 Sci-Fi Shows That Ended On Infuriating Cliffhangers

Mysteries are central to sci-fi stories, especially television series. The element of the unexplained frequently adds tension and complexity to what the characters are facing and is typically a major driver of the action, keeping audiences hooked episode to episode and season to season. With mysteries being so important to the sci-fi experience, cliffhangers also play a major role. They make for an exciting and sometimes frustrating twist, taking audiences right up to the edge of a major development or breakthrough only to force them to wait for a new episode to see how things play out.

Except, not every sci-fi series gets the chance to deliver on what those cliffhangers tease. There are quite a few series that presented fans with major cliffhangers only for the series to end right after, sticking fans with unanswered questions and a deep sense of wondering what happened next. Here are seven sci-fi television series that ended with deeply frustrating cliffhangers, some of which we are still trying to figure out years after screen cut to black.

7) The Society

Released in 2019, Netflix’s The Society wasn’t exactly supposed to end on a cliffhanger. The series followed a group of high school students who found themselves dealing with a chilling mystery when they returned home from a cancelled field trip to find their town cut off from the rest of the world and all the adults mysteriously gone. The kids were forced to set up their own society for survival, but something about the situation they found themselves in didn’t quite add up. It was in the Season 1 finale that fans were hit with a stunning revelation as to why: the adults were in some sort of parallel universe, alive and well with the teens seemingly the ones who were missing.

It was a wild set up for the second season which presumably would have explored the idea of which reality was the real one and the series had been renewed for a second season. Unfortunately, while the second season was reportedly in pre-production, that renewal was reversed with Netflix citing COVID-19 related scheduling issues. It was a major gut punch to fans, especially since the series did such a good job with its Lord of the Rings-adjacent teen story and building up to the wild turn about the adults. We’ll never get over this one.

6) Quantum Leap (1989)

The original Quantum Leap is a series that got a solid run but still ended on a cliffhanger that haunts fans to this day. The general premise of Quantum Leap followed Dr. Sam Beckett who leaped through time (the titular “quantum leap”) but this wasn’t a standard time travel situation. Each leap saw Sam inhabit someone else’s body and life, sent there to correct a wrong. Each episode saw Sam, with the help of his holographic best friend Al, try to fix the past and correct the wrong before he would leap again, always with the hope that the next leap would take him back to his own life.

For the series’ fifth season, the season finale needed to serve as a series finale in case it wasn’t renewed and when it wasn’t, the finale was devastating. Sam makes a leap that reveals to him that he actually can control where he goes and he opts to leap into Al’s past. The title card closing things out reveals that Sam never makes the leap home. That’s it. No real ending. Making things even more frustrating, years later it came to light that there were multiple endings actually filmed — including one where Al and his wife Beth try to figure out how to bring Sam home.  Decades on, we don’t know which is worse: Sam never making the leap home or the idea that there might have been a reality where he did.

5) DC’s Legends of Tomorrow

Sometimes when a series is coming up on the end of a season with a renewal not in hand, they take a risk in which they set up for an exciting continuation of the story to help nudge said renewal into reality. It’s a strategy that does work now and again. But it’s also a strategy that often doesn’t pan out and that’s what happened with DC’s Legends of Tomorrow. The wackiest series in The CW’s Arrowverse, Legends never really followed anyone’s rules but it’s also didn’t get a chance to fully land when it came to the end. Season 7 of the series ended with the introduction of Booster Gold (Donald Faison) but it also sees the heroes arrested but what are essentially time police. The episode also saw Sarah Lance reveal that she was pregnant leaving everything in a wild place.

When the series wasn’t renewed — which, on some level, wasn’t a huge surprise since most of the Arrowverse was starting to wind down around that time — series showrunner Keto Shimizu later explained that the finale was written in such a way that they had hoped it would be “undeniable to get another season”. Unfortunately, the call came down and now we’re left to wondering what happened to the heroes next though while it’s frustrating, there is something extremely Legends about an up in the air sort of ending.

4) The Whispers

ABC’s The Whispers was a series that seemed like it would have had everything going for it. Steven Spielberg was the executive producer, it was based on a Ray Bradbury short story, and it had some solid talent in its cast with Lily Rabe and Milo Ventimiglia, and the premise was solid, too: aliens are manipulating a town’s children and having them carry out heinous attacks. However, the series ended after one season, and that season ended on a cliffhanger.

The final episode sees the alien Drill abduct a group of children and the final scene shows the kids on an alien space ship as it takes off while their families are left behind to watch in horror. The moment left viewers with tons of questions that will forever go unanswered.

3) ALF

Every 1980s kid knows the pain of this particular cliffhanger. In the ‘80s, ALF was a wildly popular sitcom that followed a furry little alien named Gordon Schumway who crash lands in the garage the Tanner family in suburban middle-class California. Nicknamed ALF (for Alien Life Form,) ALF ends up becoming part of the family as they try to hide him from the Alien Task Force. Over four seasons, there are plenty of humorous shenanigans as the family and alien coexist, including the running gag that ALF wants to eat the family cat, Lucky.

The series ends with ALF hearing from his alien friends that they’ve established a New Melmac colony and want ALF to join them. However, as ALF is about to depart Earth to go to his new “home”, ALF is captured by the government. As if that wasn’t bad enough, the episode’s original ending was a “to be continued…” as NBC hadn’t actually cancelled the series until after the episode aired, which means that fans didn’t realize immediately that they were going to be stuck with this giant question mark about ALF’s fate. Things are also exacerbated by the fact that ALF is the rare series that actually did get to wrap things up, but not in the way fans might have hoped. Six years after the series finale, a television movie, Project: ALF continued the story and resolved things — but by that time most fans had moved on.

2) FlashForward

FlashForward is another one-season sci-fi series that ended on a crazy cliffhanger, but it’s also a sci-fi series that desperately deserves a second chance because of its fascinating and complex story. In FlashFoward, a mysterious, brief blackout hits the world and causes everyone to “flash forward” to six months in the future for just a brief moment. FBI agents work to investigate what happened, why it happened, and if it will happen again.

And it does happen again, The final episode saw a second blackout on the exact date the first flashforward sent them to, only this time, the flashforwards are to varied future dates and chaos ensues. The stakes had been raised, things were more exciting than ever, and that was just it. The series was cancelled. The one silver lining for this one is that FlashForward was based on the book of the same name so you can arguably find out roughly what happened, but because the television series was a loose adaptation, it’s not quite the same (though the novel is fantastic and you should absolutely read it.)

1) Sliders

The ending of Sliders is one that is so frustrating that we not only will never get over it, but it’s so intense that many fans feel like the show needs a reboot just so we get some resolution. Over the course of five seasons, the series saw a group of people who travel (aka slide) between parallel universe Earths but a mishap with the technology that allowed them to do so via wormhole created a situation where they lost track of their home universe, forcing them to slide from universe to universe hoping they’ll slide home. Think of it as a multiverse Quantum Leap of sorts.

The series finale saw two developments that have haunted fans for years. First is that Quinn merged with an alternative universe self, but it was left up in the air whether he survived the next slide or not. The second is that the other sliders “slid” again, but where they landed was never revealed. The series just ended, no answer about any of the characters’ fate was given and it has literally never been addressed. More than two decades on, we still want to know what happened and while there has been talk of a reboot or a revival, nothing has materialized and we’re still stuck wondering what happened.

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