Foreshadowing / Spider-Man: Far From Home

• Right before Peter goes to buy the necklace for MJ, Quentin Beck can briefly be seen out-of-costume in the crowd, hinting that he's been trailing Peter this whole time.
• Just before the water elemental attacks, multiple groups of twin wakes can be seen in the water of the canal, being caused by Beck's submerged drones.
• When Peter meets Beck for the first time, he calls him Mysterio after the Italian news's description of him. Beck is bemused and prefers to be called by his real name. The next time Peter meets him again, Nick Fury is about to introduce Beck by his real name only to be interrupted by Beck himself, who insists on being called Mysterio. This is a sign that he is not as humble as he seems.
• Beck, in his introduction to Peter, explains that he's a superhero from another universe where the four elementals invaded and destroyed his world and killed his family, and he wants revenge. His cliché-ridden story, badass but trite quips, and the wooden way Jake Gyllenhaal delivers the good-guy dialogue foreshadow that Beck is lying about it all.
• When Beck introduces the multiverse concept, Fury explains that Beck is from Earth, "just not yours". That's because Fury is actually Talos and isn't from Peter's Earth
• A clever one is during the scene where Mysterio claims to be from an alternate Earth (Earth-833). He calls the Earth he and Spider-Man are presently on is "Earth-616", which is the numbering for the Earth in the main Marvel comics. This hint is a Genius Bonus for those familiar with the Prime continuity canon, since the MCU actually takes place on 'Earth 199999'. While there's no reason to expect a being from another universe to follow our numbering scheme, it is still a sly tip-off towards the fact that Mysterio may not be a true multiversal traveller.
• Mysterio's leitmotif sounds like your typical heroic orchestral piece, but has a prominent use of electronic synths and gets darker and more sinister as the piece progresses. This foreshadows, in music form, how his true nature is nowhere near heroic and all his heroics were staged using drones and hologram projectors.
• The reveal that there's now a satellite carrying thousands of small, lethally-armed drones that can be deployed in an instant anywhere in the world, and that EDITH controls it all, means trouble similar to Project Insight.
• Beck says that the fire elemental can absorb surrounding metal through contact, but never gets into why it can or why what is supposedly an embodiment of natural order cares about refined earth. The answer being it doesn't — Beck just needed something to make it look like it could become a bigger threat while threatening to target a substance that is everywhere. Fury and Hill send each other looks of incredulity but don't question it openly.
• During Mysterio and Spider-Man's rooftop conversation, although they're sitting very close together, Mysterio never actually makes physical contact with Spider-Man, and has to search slightly to make eye contact with Peter. That's because the "Flying Mysterio" we see is just an illusion.
• When fighting the fire elemental, Peter's web shooters are at one point blocked by something he can't see. It's a major sign that something more is going on. MJ picks up the web and the piece of metal it caught on, and she and Peter discover the device is part of an advanced drone with hologram projectors.
• Not a single person gets visibly burned by the fire elemental even when it grows large enough to fill the entire Prague square, even Beck when he flies straight into it. This is an early hint that while there is something physically present where the fire elemental supposedly is, it's not giving off any more than the normal amount of heat.
• Similarly, Beck's costume doesn't appear to be all that physically protective, nor is there any indication that he has super-durability, yet he takes just as much punishment as Spider-Man, if not more, when fighting the Elementals, even after he flies straight into the Fire Elemental. Because the Mysterio we see taking damage is just a projection, and the real Beck is never in the danger zone.
• Peter telling MJ that "The news never lies" is a serious case of Tempting Fate that comes back to haunt him big time in the Mid-Credits sequence, wherein Jameson brands Spidey a murderer and terrorist courtesy of Mysterio's dying message video.
• While still in his "Night Monkey" guise, Peter Parker tries to ask a random woman for directions, only for the woman to freak out, yell "Night Monkey!" and flee in terror. This type of reaction doesn't really make sense because if she knows of the new moniker "Night Monkey" then that means she saw the news reports of "Night Monkey" helping Mysterio, and saving citizens at the carnival. It's the first tip-off that Peter just entered a hallucination/simulation by Mysterio. Thanks to the woman, he would want to get out of public before anyone called the police.
  • She yells "Nacht Monkey!" It sure is weird that she switches to another language under shock instead of yelling "Nachtaffe!" You may have assumed that was for the audience's benefit, except it turned out the audience was Peter.
• Peter accidentally breaks the seat belt in the car. Which is odd, because he wasn't even pulling that hard. He's later shown to be in a random old junker covered in holograms, not an actual brand-new Audi maintained by SHIELD. And as we've seen elsewhere, SHIELD vehicles, especially Fury's, are very tricked-out (and durable). Why wouldn't the SUV be 'secure'? Because Beck wants an excuse not to talk.
• The fact that the Nick Fury who meets Spider-Man in Berlin is really Beck is foreshadowed by his reaction when the illusion of the phony Europol headquarters starts to fade and he acts completely shocked, despite being the one who drove the car there. He had to know beforehand he was in the wrong building.
• There are several subtle tells throughout the movie that Fury and Hill are actually Talos and Soren.
  • Hill calls Fury "Nick" in the first scene. Captain Marvel made it abundantly clear that nobody is on a first-name basis with Nick Fury.
  • Fury tells Peter that Beck is from Earth, "just not yours" rather than "just not ours".
  • Fury seems uncharacteristically willing to take the fact that Beck is from another Earth at face value. The reasons for this are twofold: one, Talos isn't the lifelong spymaster that Fury is, and so isn't quite as good at spotting a fake on sight. Two, Talos isn't quite as surprised at seeing someone who's not from this Earth, because, well, neither is he.
  • The excuses that Fury gives Peter for why they can't call in other superheroes than Spider-Man are pretty flimsy; while Thor is off-world with the Guardians of the Galaxy, there's no reason Doctor Strange would be indisposed. And even putting aside them specifically, there's dozens of other heroes they could contact who would probably be able and willing to help, and would be much better equipped to fight the Elementals, including heroes who have experience with cosmic/mystical-level threats (Wong and Valkyrie, for instance). But Fury claiming there's no one but Peter makes more sense if you consider Peter is a teenager who is easily intimidated by Fury and eager to prove himself and will do as he's told — i.e., he's unlikely to get suspicious about Fury and won't question any unusual behavior from him. For that matter, Peter hasn't met Fury in-person yet while many other heroes have, another good reason to contact him.
  • The reverent way Fury refers to Captain Marvel, telling Peter not to "invoke her name," as if Peter hadn't earned the right to mention her. Nick may hold Carol in high esteem, but not that kind of high esteem.
  • When Peter says he's not up to the task of being an Avenger since he's a Friendly Neighborhood Spider-Man, Fury responds, "Bitch, please! You've been to space!" No wonder "Fury" is so aware of the dangers of outer space... he's from outer space.
  • While always a cold person, Fury knows the difference between giving a person a kick in the ass to get them working and breaking someone down, which makes the fact that Fury gets pissed off at Parker raise a few flags. Tony had done far worse than endanger his friends, but Fury simply expressed his disappointment and got him back to work. It makes sense that Fury could lose his cool at Peter since he's actually Talos posing as Fury, so he was acting as he thought Fury would act and missed the mark.
  • Fury is indignantly discussing Kree sleeper cells with Hill when he's interrupted about the impending London attack. Fury would be very unlikely to concern himself with Kree sleeper cells, simply because there's unlikely to be any on Earth.
  • The fact that Fury was fooled by Beck so easily is the biggest clue that it really wasn't him. As Beck himself points out, Fury is the most paranoid person on the planet. Although Beck is well aware of Fury's paranoid nature and is trying his damn hardest to fool him, coming up with a foolproof backstory and backing himself with an entire team to ensure his charade doesn't fall short, the fact that Fury never doubted Beck's story, not even once, and presumably never tried to do a background check on him (no matter how seemingly futile it would've been), is very unlike Fury, who would've only grown more distrustful and paranoid of unknown factors after The Winter Soldier. Talos, however, is familiar with the cosmic world thanks to being an alien, so he would be a lot more accepting of Beck's cover story at face value than the real Fury would.
• After Spidey disables some of the drones and blows Mysterio's illusions, Riva contacts him that the glitches are widely visible, but Mysterio smirks and tells him he has planned for it, while sending Riva his drone recordings. By The Stinger, it is evident those are his emergency recordings in case Peter manages to beat him, which prove instrumental in exposing Spider-Man and ruining his reputation.
• Before Mysterio dies, he tells Peter that people will believe anything, as proven by the countless citizens who were tricked by his illusions. At the end, Beck successfully fools everyone into thinking that Spider-Man was the culprit behind the attack.
• E.D.I.T.H.'s acronym is for "Even Dead, I'm The Hero". Thanks to his doctored footage, Beck manages to posthumously portray himself as a hero, with J. Jonah Jameson even referring to him as such, while simultaneously framing Peter for both his actions and his murder.