There are few things more upsetting than a disappointing ending, as it has the potential to ruin an otherwise enjoyable film. Even if a film has a terrific opening scene and strongly written characters, an ending that fails to live up to expectations can leave viewers with a sour taste in their mouths. This is particularly true within the science fiction genre, where the success of a film’s ending plays a significant role in how rewatchable it is.

When looking at the best science fiction films of all time, classics like 2001: A Space Odyssey, Aliens, Blade Runner, and Robocop all end on a high note. Unfortunately, many films may be denied the opportunity to become classics because their final moments ruined what would have otherwise been a successful story. These great science fiction movies would have much better legacies had they not been ruined by their terrible endings.

10 ‘Star Trek: Generations’ (1994)

Directed by David Carson

Star Trek: The Next Generation was immensely successful and, in many ways, eclipsed Star Trek: The Original Series. Although the first film starring the show’s cast, Star Trek: Generations, promised to bring together Captain Jean Luc-Picard (Patrick Stewart) and Captain James T. Kirk (William Shatner) for the first time, it sadly didn’t give the characters much time to spend together.

To make things worse, Kirk dies in the film’s ending and is not given a proper burial by his fellow Starfleet officers. The ending of Star Trek: Generations ruined the good finale of Star Trek VI: The Undiscovered Country, in which Kirk and his crew celebrated their victory. Having Kirk go out so disappointingly was frankly disrespectful to the legacy of one of science fiction’s most legendary heroes who should have at least put up a fair fight.

9 ‘The Lost World: Jurassic Park’ (1997)

Directed by Steven Spielberg

Considering that Jurassic Park had become the highest-grossing film of all time and one of the most acclaimed films of Steven Spielberg’s career, The Lost World: Jurassic Park had to live up to tremendous expectations. The film actually works fairly well as an adaptation of Michael Crichton’s novel of the same name, but the last act of The Lost World: Jurassic Park takes the story to San Diego in a move that defies all logic.

It essentially turned what was, up until that point, a compelling dinosaur survival movie into a monster movie similar to Godzilla but with a far less engaging monster. Unfortunately, The Lost World: Jurassic Park set up a dangerous precedent for the series in which the sequels tried to top the original film’s spectacle. It’s perhaps unsurprising that subsequent entries in the Jurassic Park series have progressively gotten worse.

8 ‘Star Wars: Episode III - Revenge of the Sith’ (2005)

Directed by George Lucas

Star Wars: Episode III - Revenge of the Sith actually made up for a lot of the mistakes of the first two installments in George Lucas’s prequel trilogy. It shows Anakin Skywalker's (Hayden Christensen) seduction into the dark side by Chancellor Palpatine (Ian McDiarmid). Unfortunately, the film ends with a very cringe-worthy moment where Darth Vader screams “NO!” after learning that he accidentally killed his wife, Padme Amidala (Natalie Portman).

Even with the return of James Earl Jones as the voice of Vader, it was hard to take this moment seriously. The ending of Star Wars: Episode III- Revenge of the Sith turned one of the greatest villains in science fiction history into a complete joke and ruined what was otherwise a compelling dark tragedy. It was a disappointing way for the last Star Wars movie directed by Lucas to end, although it does speak to his more cheesy sensibilities.

7 ‘I Am Legend’ (2007)

Directed by Francis Lawrence

I Am Legend is one of the best post-apocalyptic science fiction films ever made, and Will Smith does a great job showing what being the last representative of the human race would look like. Although it begins as an exciting celebration of what mankind can accomplish when put in extreme danger, I Am Legend ends with a shocking twist in which Smith’s character dies.

Those expecting a rousing call to action likely left the theater disappointed by the depressing ending that offered no sense of encouragement or insight. The ending of I Am Legend became so notoriously terrible that many audiences simply preferred the alternate ending included in the DVD in which Smith’s character lives. In fact, the upcoming sequel is set to adopt the alternate ending and will feature Smith reprising his role alongside Michael B. Jordan.

6 ‘Knowing’ (2009)

Directed by Alex Proyas

While Nicolas Cage often gives over-the-top performances where he gets to chew the scenery, the actor actually turns in a very respectable dramatic performance in the science fiction disaster film Knowing. Cage stars as a professor who discovers connections between different disastrous events that have been prophesied by a time capsule. Knowing ends by revealing that the disasters were predicted by aliens who visit Earth to help transport children to their homeworld. Cage’s character is forced to simply stand by and bid farewell to his son.

While it was an interesting idea in theory, Knowing does not share enough information about the aliens’ motivations in order to make this a satisfying ending. To make matters worse, the somewhat cheesy computer-generated imagery within the last few moments of the film makes Knowing far more laughable than it is powerful.

5 ‘The Wolverine’ (2013)

Directed by James Mangold

Although Hugh Jackman’s first solo outing as his most famous character in X-Men Origins: Wolverine was a complete disaster, The Wolverine was a fairly compelling solo film that brought some fun yakuza-style action to the X-Men film franchise. James Mangold took a grittier approach to the source material, but the ending of The Wolverine featured an over-the-top CGI battle between Logan and the “Silver Samurai” that simply looked cheesy.

The Silver Samurai is not a well-developed villain that could feasibly challenge Logan in this climactic moment. At least it was fun to see Professor X (Patrick Stewart) and Magento (Ian McKellen) return, even if the post-credit scene of The Wolverine also proved entirely pointless. The subsequent film, X-Men: Days of Future Past, effectively negated the events by taking place in an alternative timeline with a different version of the characters.

4 ‘Lucy’ (2014)

Directed by Luc Besson

Lucy was a great female-centric sci-fi action thriller that starred Scarlett Johansson as a woman with the ability to unlock the fullest capabilities of the human brain. The film invokes sympathy for Lucy, as, despite her increased powers, she is still a vulnerable human who is not entirely robotic. However, Lucy's ending effectively turns her into a superhero who can infect entire computer systems.

While director Luc Besson has proven with films like Leon: The Professional and The Fifth Element that he can create transporting action sequences, his skills as a writer are far less well-developed. Lucy’s writing becomes increasingly hackneyed in its final act, as Besson fails to adequately explain the thought-provoking concepts about mankind that he is attempting to explore. Even Johansson’s great performance can’t prevent Lucy from being far too confusing.

3 ‘Alien: Covenant’ (2017)

Directed by Ridley Scott

Alien: Covenant is a very interesting installment in the infamous science fiction horror franchise, proving that the great Ridley Scott still had it in him to produce some good scares. The most compelling aspects of Alien: Covenant involve the character of David (Michael Fassbender), an android experimenting with the creation of the Xenomorphs. While the ending of Prometheus suggested a bold new future for the series, Alien: Covenant ended with a generic Xenomorph slasher scene that felt like a complete ripoff of Alien and Aliens.

Whereas Prometheus dared to challenge fan expectations by changing up the mythology of the series, Alien: Covenant was cowardly nostalgia bait that avoided doing anything different. The film’s underperformance resulted in the series not being able to continue, leaving many plotlines in both films unresolved.

2 ‘Glass’ (2019)

Directed by M. Night Shyamalan

M. Night Shyamalan pulled off one of the biggest plot twists in recent years with Split, in which he revealed that both David Dunn (Bruce Willis) and Elijah Price (Samuel L. Jackson) existed within the same universe as Kevin Wendell Crumb (James McAvoy). Although the stage was set for an exciting showdown between the three super-powered characters, Glass ended by killing them in a disappointing fashion.

To make matters worse, the revelation about a secret organization monitoring those with superpowers could have been seen coming from a mile away. The ending of Glass indicates that Shyamalan doesn't understand the superhero genre. While the film aimed to be a “deconstruction” of the roles that superheroes played in society, it ended up with a generic action sequence that didn’t feel all that different from what audiences could see in a Marvel or DC film.

1 ‘Ghostbusters: Afterlife’ (2021)

Directed by Jason Reitman

Ghostbusters: Afterlife is a fairly lovely tribute to the legacy of the original Ghostbusters, and for the most part, it does a great job at setting up the new heroes Phoebe (Mckenna Grace), Trevor (Finn Wolfhard), and their mother Callie (Carrie Coon). However, the ending makes the strange choice to feature a CGI recreation of the late great Harold Ramis as his original Ghostbusters character, Egon Spengler.

Seeing a dead actor brought back to life for nostalgia's sake was more than a little unnerving, especially considering that the film already featured cameos from Bill Murray, Sigourney Weaver, Ernie Hudon, and Dan Aykroyd. Afterlife is one of the most rewatchable Ghostbusters movies, but the ending does make the tone more than a little odd compared to the beginning.