Cinemas are packed full these days with sequels and franchises, so you can't really blame movies for trying to set up future adventures.
Of course, not every movie can get the sequel it desires – some of them tank, some get a critical mauling. That's fine if the movie works as a standalone, but it is a bit awkward when it seems to blatantly set up a sequel that never comes.
New horror movie Escape Room could fall foul of this with its tacked-on sequel-bait ending (it performed OK at the US box office, but received soft reviews), so that led us to look back at the other films that unashamedly set up a sequel, only to never get one.
(Note: We've avoided movies that were planned to start a wider franchise, like The Mummy (2017) and King Arthur: Legend of the Sword, and focused on direct sequels.)
1. Tomb Raider (2018)
We might be being a little presumptuous about this one, but last year's Tomb Raider reboot with Alicia Vikander as Lara Croft didn't exactly set the box-office alight or excite the critics, although its overseas total could still lead to a sequel. It worked for Percy Jackson…
It certainly wants one because after Lara saves the world and escapes the tomb (which would have been a perfectly good ending), she heads back to London and realises that her father's business partner has been a baddie all along. As an added bonus, we get the iconic shot of Lara holding two guns from the game in a credits scene.
2. Green Lantern
Ah Green Lantern. Everyone's go-to terrible superhero movie and one that even its star Ryan Reynolds mocks these days. But Warner Bros had high hopes that their movie would not only get a sequel, but kickstart a whole new DC movie franchise.
The film features a mid-credits sequence that sees Hal Jordan's mentor Sinestro putting on the yellow power ring, beginning his transformation into the villain from the comic books. Mark Strong never got to go full villain, though, as Warner Bros cancelled plans for a sequel and is now rebooting the franchise.
3. Fantastic Four (2015)
What's that, you want another terrible superhero movie? Step forward Josh Trank's 2015 reboot of Fantastic Four, which stands at a painful 9% on Rotten Tomatoes. But the future originally looked so bright.
Fox had set a release date for the sequel even before Fantastic Four was out, before removing it from the schedules altogether, paving the way for them to be rebooted (again) in the MCU. So it's understandable that the movie lays the groundwork for a follow-up.
That still doesn't excuse the terrible ending that sees Reed Richards suddenly come up with the team name, mind.
It's fairly commonplace for horrors to end with a quick shock that lets the audience know that things might not be as over as you think. Usually it's just for the scares, but Slither – Guardians of the Galaxy's James Gunn's directorial debut – is a bit different.
The horror-comedy about malevolent alien slugs that turn victims into hideous monsters appears to end on a fairly definitive note, only for the post-credits scene to show an unfortunate cat being infected by a still-alive slug. Sadly, Slither was a box-office bomb and that put paid to any chance of a sequel.
5. The Amazing Spider-Man 2
Sony were preparing for big things with The Amazing Spider-Man 2, using Marc Webb's sequel to launch a competing comic-book universe to rival the MCU. As such, the movie was stuffed with setup for both The Amazing Spider-Man 3 and spinoffs like Sinister Six.
It was to the movie's detriment and highlighted just why Marvel's 'less is more' franchise-building approach works best. Of course, it must hurt all the more now that Spidey's had a successful reboot in the MCU and any future Amazing Spider-Man outings were cancelled. At least Sony has since had better universe-building success (somehow) with Venom.
6. Godzilla (1998)
Hollywood's first attempt at Godzilla was meant to be the start of a trilogy, which is why it ends on a sequel tease. After the day is supposedly won, the camera cuts back to Madison Square Garden to reveal that one of Godzilla's eggs survived – and it's just hatched.
But despite the best efforts of Matthew Broderick and Jamiroquai, the movie didn't make enough money to convince Sony to make a sequel. It did however get an animated TV show sequel that ran for two seasons, which retconned the movie ending to have a doctor discover the surviving egg before it hatched.
7. Super Mario Bros
Okay, so we're not exactly surprised that notorious flop Super Mario Bros didn't get a sequel, but you've got to applaud its belief that it could warrant one. That's why it ends with Daisy returning to the brothers to get their help on a new adventure.
We might not have seen that adventure (and what they're "never gonna believe") on screen, yet the movie did at least get a comic-book sequel. This followed what happened when the trio returned to Dinohattan and battled with frog king Wart, taken from the second game.
8. Masters of the Universe
More than 20 years before Nick Fury showed up in Iron Man's post-credits scene, Masters of the Universe was rewarding viewers who sat through the credits with a sequel tease.
The now-cult fantasy has a post-credits scene that sees Skeletor emerge from the pit he was thrown into by He-Man at the end of the movie, promising that he'll "be back". Well, the film was a box office flop, so funnily enough, Skeletor never did come back.