It’s common for science fiction shows to end episodes with cliffhangers to keep viewers hooked and wanting more. The classic series Doctor Who was famous for this, telling stories in segments of four to six parts, and each part always ended with a suspenseful moment.
Most science fiction shows today tell a complete story each episode, but they frequently end their seasons with a cliffhanger to keep viewers engaged until the next season. This is a great way to build anticipation. Unfortunately, some promising sci-fi series have been canceled too soon, without a chance to finish their storylines. This has left fans frustrated with unresolved plots and characters left hanging.
7) Dark Matter’s Intergalactic War Won’t Be Fought
The TV show Dark Matter on ABC (different from the newer sci-fi series of the same name) started with a fascinating idea: a group of strangers wake up on a spaceship, completely unaware of their pasts or how they ended up there. Throughout the show’s three seasons, these people discover they used to be criminals, but ultimately transform into heroes battling powerful enemies.
Their final, major conflict was never resolved. The season 3 finale left Earth facing an alien invasion by the Black Ships, with the crew broken up – one member killed and another captured. This dramatic ending was meant to launch a new intergalactic war, but the show was canceled, leaving the crew’s fate – and the future of Earth – uncertain forever.
6) FlashForward’s Alternative Future Can’t Be Resolved
As a huge sci-fi fan, I really wish more people had given FlashForward a chance. It was sadly canceled, but it’s a show that deserves a revival. The premise was so intriguing: everyone, all over the world, momentarily blacked out and saw a glimpse of their future. While most of us would be freaking out trying to figure out what it all meant, the FBI was tasked with finding out why it happened in the first place.
The final episode of the first season also turned out to be the last episode ever made, as the show was canceled. It was a high-stakes hour, featuring a second global blackout, but this time, people glimpsed a changed future. The episode included dramatic scenes like characters waking up from comas, children reacting with fear, and a confrontation with the FBI.
I was so captivated by the hints of what was to come in season two! It was shaping up to be amazing, but then ABC canceled the show, and honestly, it broke my heart. Now we’ll never know who was behind those mysterious blackouts or what the meaning of those intriguing flash forwards was. It feels like a real loss, and I’m so disappointed for the characters – and for all of us fans.
5) The Whispers’ Children Will Forever Be Stuck on An Alien Ship
The third ABC show to be cancelled after one season was The Whispers, which aired in 2015. The show featured Milo Ventimiglia, who later became known for This Is Us, and had a creepy premise: aliens were controlling children and using them to attack Earth.
The first season ended with a shocking twist: aliens kidnapped several children and flew them away on their spaceship. This left viewers wondering what the aliens intended to do with the kids, and if their parents would even notice they were gone—or worse, if the aliens would erase their memories. Unfortunately, we’ll never get answers, as the network, ABC, decided to cancel the show before the story could be finished.
4) The Society’s Biggest Mystery Remains Unsolved
Netflix’s The Society was a compelling teen drama with a sci-fi twist. The show followed a group of students who found themselves mysteriously back in their hometown, but everyone else was gone. They had to build a new community from scratch, learn to survive, and figure out if they’d create a chaotic world like in Lord of the Flies, or choose to live together peacefully.
The first season of the Netflix show ended with a shocking twist: the adults were actually in a different reality, grieving the disappearance of their children. Unfortunately, we’ll never get answers about which world was the ‘real’ one or if the kids ever found their way back home, as the show was canceled by Netflix due to difficulties with filming caused by the pandemic.
3) The Fate of the Sliders Crew Is Forever Unknown
Sliders is a sci-fi show that’s ripe for a revival, mainly because its original ending was so unsatisfying. The show followed characters traveling between different universes in search of their own, and the final episode of its five-season run left viewers with a lot of unanswered questions.
In the last episode, Quinn combined with his counterpart from another universe, and it was left uncertain if this merged Quinn would survive. The rest of the team then entered another wormhole, but their destination remained a mystery. The show ended on this cliffhanger, frustrating viewers who were left without any resolution to the characters’ stories, a situation made worse by the fact that a planned revival of Sliders never happened.
2) The Fate of Alphas’ Dr. Rosen Forever Remains A Mystery
As a big fan of both superhero stories and crime dramas, I really enjoyed Alphas. It took the idea of people with special abilities – kind of like the X-Men – and put it into a police procedural setting. The show followed a team of uniquely developed characters with extraordinary powers who worked with the government to track down others like themselves. What I particularly loved was that they weren’t just about using their powers; the show really delved into the tough moral questions they faced.
The second season concluded with the world bracing for a war between Alphas and humans. The final episode showcased a dramatic battle that started when Dr. Rosen sent out a signal, seemingly causing widespread deaths – including what looked like his own, as he suddenly collapsed.
The last scene resembled something out of The Walking Dead, showing a street filled with bodies, but it was unclear if it was genuine or a trick. Viewers were also left wondering if the character Rosen survived the attack, as the show was canceled by SyFy before the mystery could be resolved.
1) Quantum Leap’s Sam Beckett Will Never Get Back Into His Original Body
The final episode of the original Quantum Leap left viewers with a famously frustrating cliffhanger. The show centered around Sam, who traveled through time by inhabiting other people’s bodies to fix past mistakes, but the entire series built towards him finally returning to his own life.
After NBC canceled the show, the producers attempted to wrap things up, but the finale didn’t quite satisfy viewers. The last episode showed Sam leaping into a timeless bar and discovering he’d been orchestrating his own journeys. Instead of coming home, he jumped into Al’s past, and a closing message revealed he never returned to his original body.
The closing title card didn’t resolve the suspense of Sam trying to save Al, and it didn’t provide a good conclusion to Sam’s story. What’s even more frustrating is that the new Quantum Leap series didn’t follow up on Sam’s fate, leaving viewers without any closure about what happened next or why he couldn’t return home.
What sci-fi plot ending left you hanging the most? Share your thoughts and discuss it with other fans at the ComicBook Forum!
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2025-10-21 19:43