Foreshadowing is a writing device that can take many different forms, and films have managed to use it in some truly mind-blowing ways.

20. Doc Ock's Death - Spider-Man 2

19. A Fistful of Dollars - Back to the Future Part II

18. The Bar Names - The World's End
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This Edgar Wright classic shows five friends going to 12 different bars and fighting an army of robots (yeah, it's pretty crazy). The name of each bar represents an event in the characters' journeys throughout the film. For example, Gary faces off against twin robots at The Two-Headed Dog, the boys are seduced by three siren-esque women at The Mermaid, and Andy drives Gary's car through the wall of The Hole in the Wall. Of course, the most explicit hint is how the Earth goes back to the Dark Ages after Gary and his friends reach The World's End.
17. Blue Sky on Mars - Total Recall (1990)
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When Douglas Quaid is setting up his false memories at Rekall, one of the technicians mentions a "blue sky on Mars" that's part of his desired dream. The film ends with blue skies appearing on the red planet, with Quaid wondering if that was all just a dream. So not only was this a clever bit of foreshadowing, but the fact that this ending was part of the dream he asked for implies that the film really was just a dream.
16. The Bird Cage Trick - The Prestige

15. The Flood - Parasite

14. The Truth About Sandie - Last Night in Soho

13. "Have You Lost Weight?" - Tag
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In a surprisingly dark twist for such a fun comedy, we learn that Ed Helms' Hoagie was diagnosed with cancer and was worried he wouldn't survive for the next game of tag. However, when Bob asks him if he lost weight during the first act, the film hints that he has cancer, as weight loss is a side effect of chemotherapy. You probably didn't expect this clever detail to be placed in a movie like this, but comedy does rely on doing the unexpected.
12. T'Challa Freezes - Black Panther

11. That Man's Playing Galaga - The Avengers
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In the first Avengers film, Tony catches one person in the S.H.I.E.L.D. Helicarrier playing Galaga on his computer. While this may seem like another one of Marvel's throwaway jokes, it actually foreshadows the alien armada that descends on New York from the sky in the film's third act. If only the Avengers had a starship to fight them off like in Galaga.
10. The Sushi - Snowpiercer (2013)

9. X Marks the Spot - The Departed

8. The Number 82 - Magnolia

7. Dust and Blood - Avengers: Infinity War

6. Just a Pipe Dream - The Shawshank Redemption

5. My First Fight With Tyler - Fight Club
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The big twist of this classic David Fincher flick is that the Narrator and his friend/enemy Tyler Durden are really the same person, and there is a small but crucial piece of dialogue that hints at this. When the Narrator beats himself up to blackmail his boss, he says in a voiceover, "For some reason, I thought of my first fight with Tyler." Gee, I wonder why?
4. The Armitage Attacks - Get Out

3. Dying Inside Yourself - Zack Snyder's Justice League
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This is a rare case of foreshadowing for a movie that hasn't been made (at least not yet). In this superhero epic, Batman encounters Joker in a hellish future ruled by Darkseid that the Caped Crusader had a role in creating. For his mistakes, Jokers claims that Batman doesn't have the guts to make the ultimate sacrifice as everyone else suffers because of him. His argument foreshadows how Batman was supposed to sacrifice himself to help stop Darkseid in Snyder's planned sequel to Justice League, proving the Joker wrong.
2. Tying the Belt Buckles - Jurassic Park

1. The Stuffed Birds - Psycho
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What is it with Hitchcock and birds? When future shower-murder victim Marion Crane suggests Norman Bates put his ill mother in a psychiatric hospital, Norman scoffs at the idea, claiming that "she's as harmless as one of those stuffed birds." This couldn't be any more true when we learn that Norman had murdered his mother years ago and placed her mummified corpse in her room like one of his avian trophies. In fact, she's so harmless, she wouldn't even harm a fly.