7 Sci-Fi Shows That Ended On Infuriating Cliffhangers

Sci-fi stories, particularly on TV, often revolve around mysteries. These unexplained elements build suspense and make challenges for the characters more complicated, driving the plot forward and keeping viewers engaged. Because mysteries are so crucial to sci-fi, cliffhangers are also common. They create exciting, though sometimes frustrating, moments by teasing big reveals or breakthroughs and making audiences wait for the next episode to find out what happens.

Many sci-fi shows build suspense with cliffhangers, but not all of them get to resolve those storylines. Unfortunately, some series leave viewers hanging with unanswered questions when they’re unexpectedly canceled. Here are seven sci-fi TV shows that ended on frustrating cliffhangers, leaving fans to speculate about what happened next – even years later.

7) The Society

Netflix’s show The Society, which premiered in 2019, unexpectedly ended with an unresolved cliffhanger. The series centers around a group of high school students who return from a trip to find their town completely isolated and all adults vanished. They had to create a new society to survive, but something felt off about the situation. The season one finale revealed a shocking truth: the adults weren’t gone, but were actually living in a different reality, while the teenagers seemed to be the ones missing from their world.

I was so hyped for season two! It seemed like they were going to really dive into which reality was actually real, and Netflix had already given the show the green light. But then, out of nowhere, they cancelled it, blaming COVID-related scheduling problems. It honestly felt like a punch to the gut. The show was doing such a great job with that whole ‘Lord of the Rings meets teen drama’ vibe, and the twist with the adults was building to something amazing. I’m still heartbroken that we’ll never get to see where it was going.

6) Quantum Leap (1989)

I remember watching the original Quantum Leap and being totally hooked! It ran for a good while, but it ended so abruptly, leaving fans like me hanging for years. The show was about Dr. Sam Beckett, who didn’t just travel through time – he became other people, stepping into their lives to fix mistakes. Every episode, he and his friend Al, who appeared as a hologram, would work together to set things right. Sam was always hoping that fixing these past wrongs would finally send him back home, but it never quite happened, and that’s what made it so frustrating – and memorable!

The fifth season finale of the show was designed to also work as a series finale, just in case the show wasn’t picked up for another season – and it wasn’t. The ending was heartbreaking: Sam discovers he can control his time leaps and chooses to leap into the past of his colleague, Al. The final title card shows Sam never returning home. It felt incomplete and left viewers with no real resolution. To make matters worse, it later came out that several different endings were filmed, including one where Al and his wife, Beth, tried to find a way to bring Sam back. Even now, years later, it’s unclear which is more upsetting: the fact that Sam never made it home, or the knowledge that there was a version of events where he could have.

5) DC’s Legends of Tomorrow

Sometimes, when a TV show is nearing the end of a season and hasn’t been renewed yet, the writers will create a cliffhanger or set up an exciting future storyline hoping to convince the network to pick it up for another season. This tactic can work, but often it doesn’t. That’s what happened with DC’s Legends of Tomorrow. The show, known for being unconventional within The CW’s Arrowverse, never quite got a proper conclusion. The seventh season ended by introducing the character Booster Gold (Donald Faison) and arresting the heroes by what amounted to time cops. On top of that, Sarah Lance revealed she was pregnant, leaving the story in a very unpredictable place.

Although the show’s cancellation wasn’t entirely unexpected, given the general decline of the Arrowverse, the showrunner, Keto Shimizu, revealed they wrote the finale hoping to secure a renewal. Sadly, it wasn’t meant to be, leaving fans to imagine what happens next. While it’s disappointing, this open-ended conclusion feels fitting for a show like Legends of Tomorrow.

4) The Whispers

ABC’s The Whispers had a lot of potential. With Steven Spielberg as an executive producer, based on a story by Ray Bradbury, and starring actors like Lily Rabe and Milo Ventimiglia, the show’s concept – aliens controlling children to commit terrible acts – was also promising. Despite this, the series was canceled after just one season, leaving viewers with an unresolved cliffhanger.

The series concludes with the alien Drill kidnapping a group of children. The last scene shows them aboard an alien spaceship as it launches into space, leaving their families devastated on Earth. This shocking ending left fans with many unresolved questions that will likely never be answered.

3) ALF

Anyone who grew up in the 1980s remembers the frustrating ending to the show ALF. The sitcom was about a furry alien named Gordon Schumway (nicknamed ALF, which stands for Alien Life Form) who crash-landed in the garage of a typical California family, the Tanners. The show followed the family as they tried to keep ALF a secret from a government agency dedicated to finding aliens. Over four seasons, the show was full of funny moments, including a recurring joke about ALF wanting to eat the family cat, Lucky.

The show concludes with ALF receiving a message from his alien friends: they’ve created a new colony on Melmac and want him to join them. Just as he’s about to leave Earth, however, ALF is captured by the government. To make things even more frustrating for viewers, the episode originally ended on a cliffhanger, with a “to be continued…” message. NBC hadn’t officially cancelled the show yet, so fans didn’t immediately realize this was the last they’d see of ALF’s story. It’s unusual because ALF actually did get some closure, but not in a satisfying way. Six years later, a TV movie called Project: ALF picked up the story and finally provided a resolution, though by that point most viewers had lost interest.

2) FlashForward

FlashForward is a sci-fi show that, despite only lasting one season, has a compelling and intricate story that deserves to be continued. The series centers around a global blackout that causes everyone to briefly glimpse six months into their future. FBI agents then investigate the cause of this event and whether it might happen again.

The show experienced a second blackout on the anniversary of the initial flashforward, but this time, people were sent to different points in the future, leading to widespread chaos. Despite the increased stakes and excitement, the series was cancelled. Thankfully, FlashForward was based on a novel, so readers can find out how the story could have ended. However, the TV show took liberties with the source material, so it’s not a perfect continuation – though the book itself is excellent and well worth reading.

1) Sliders

The finale of Sliders is notoriously unsatisfying. Many fans are still upset by it and believe the show needs to be revived just to provide a proper conclusion. The series followed a group who traveled between alternate versions of Earth, but a malfunction with their portal technology left them lost, endlessly sliding from one universe to another in hopes of finding their way home. It’s similar to Quantum Leap, but with a multiverse twist.

The series finale of the show left fans with two major unanswered questions that still bother them today. First, Quinn merged with a version of himself from another universe, but it’s unclear if he made it through the subsequent jump. Second, the rest of the team slid to a new dimension, but their destination was never shown. The show simply ended without resolving anything about the characters’ fates, and this has never been addressed in any follow-up. Over twenty years later, fans are still hoping for closure, and while there’s been discussion about bringing the show back, a reboot or revival hasn’t happened, leaving us to continue wondering what became of everyone.

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2026-02-17 00:15