5 Reasons Marvel Fans Are Freaking Out Over 'Avengers: Infinity War' Trailer

The sneak peek was packed with new footage of Earth's Mightiest Heroes crossing paths with the Guardians of the Galaxy and taking on the most powerful villain to date, Thanos (who looks a lot like Steve Austin -- Happy Stone Cold Day!). Though exciting, the video also left Marvel fans wondering which -- if any -- of their favorite superheroes would survive the battle.

We're sure you did, but just in case you didn't -- watch the trailer first, then take a look at what Twitter is freaking out over. Warning: Potential spoilers ahead if any these theories turn out to be true!

So far, Jeremy Renner's Hawkeye has been totally MIA from any and all publicity materials for the movie. He's not in either trailer, was not in the footage shown at Comic-Con or D23, isn't in any posters and was not included on any of the 15 Entertainment Weekly covers for the movie.

"Hawkeye coming out of Civil War is in the same position that the Cap and Falcon are in at the end of that movie," director Joe Russo explained. "And coming into this movie, the characters who are on Cap's side coming out of Civil War, some made certain decisions and others made other decisions that led to different paths and them dealing with oversight in this movie in a different way. So, Hawkeye's on his own journey in this movie. He has a unique reaction to the Civil War situation that puts him in a special spot this film."

OK, but what does that mean? Will he even appear in the movie at all? Our guess: He's chilling with his family on the farm, and will re-enter the fold when something happens to those he loves ... either his family, or one of the Avengers. Ant-Man is also MIA.

At first glance, it appeared as if Thor (Chris Hemsworth) was getting his head crushed by Thanos as his mischievous brother, Loki (Tom Hiddleston), watched. But a closer look at stills from the trailer reveals a different possibility: Thor is actually being forced to watch Thanos execute his brother, who finally seemed to become a good guy by the end of “Thor: Ragnarok.” Thor isn't screaming out in physical pain, but rather emotional pain when the big bad guy holding his head gives the order to kill the God of Mischief once and for all. Or perhaps Loki tries to trick the Stone Cold Steve Austin doppleganger with a fake tesseract, which doesn't end well for Loki.

We think fans have good reason to be worried about Loki, too. The end of "Thor: Ragnarok" teased the Asgardian brother's ship being approached by a much larger one, which we assume is Thanos, and then we assume the Guardians of the Galaxy come to the rescue, for Thor at least, since he makes one more appearance in the trailer, with teenage Groot witnessing a lightning shower. (Perhaps a release of rage after his brother bites the dust?)

No, you are not. It appears Loki's fate is a global concern.

But Loki's death would just be an appetizer for the destruction Thanos will bring to the MCU. Tony Stark -- aka Iron Man, who's basically the face of the entire franchise at this point -- may also sacrifice his life for the cause. His death would be MAJOR, but we can believe it since Robert Downey Jr. has played the Marvel superhero for 10 years now. Might be time for him to move on as an actor, and Marvel executive Kevin Feige has said that the next phase of the MCU will put new superheroes front and center to anchor the interconnected movies.

Oh, plus Downey already promised death in "Infinity War."

"Believe me, I'm tired of every movie, you know, 'It's the end! It's Armageddon! It's the be-all, end-all forever!' And then it's... not," Downey said in an interview. "This one actually is. They're not kidding. This is a heads-will-roll scenario."

We doubt his PG-13 death would be that gruesome -- but how crazy would it be if we look back at that interview in a few months and realize Downey was literally teasing how Tony Stark dies? Either way, there are no shortage of people who suspect Stark is in mortal danger.

Along with Tony Stark, Captain America is the other one most fans are worried won't make it out of "Infinity War" alive.

After going into hiding following the events of "Civil War," he pops up in the trailer in Wakanda, joining arms with Black Panther, Black Widow, Hulk, Bucky and Falcon to take on Thanos' army. The second to last shot of the sneak peek shows him battling the Mad Titan with his bare hands, something we wouldn't recommend to anyone who wants to keep breathing.

Evans' contract is one that's coming up on its expiration date as well, meaning Marvel will either kill him off or renegotiate. With a heroic arc under his belt already, it might be time for him to hang up his shield and hand it over to Bucky Barnes.

Thankfully, the tweets about Peter Parker aren't as life threatening as the rest, as most people are just calling out how adorable Tom Holland is as Spider-Man.

Thanks to a shiny new suit and a new 'do, the web-slinger got himself a makeover that most seem to approve of. Making the stakes a little less dire for Spidey: he has a "Homecoming" sequel scheduled to come out two months after the fourth "Avengers" film.

"Avengers: Infinity War" opens April 27, 2018. Advance tickets are already on sale at Fandango.