First off, even though this is a rumor, there could possibly be SPOILERS ahead for Avengers: Infinity War, so read ahead at your own risk. A new rumor states that a major Marvel Cinematic Universe character will die at the very beginning of Infinity War, setting the dark tone for the rest of the movie. The rumor carries some weight since the first 30 minutes of the movie have been screened in select locations around the world. However, lucky viewers had to sign Non-Disclosure Agreements to prevent leaks of any kind, so we'll take this rumor with a grain of salt.

The new report about a major death at the very beginning of Infinity War comes to us from Screen Geek, who claim to have a trusted source who went to the one of the mini-screenings of the movie last week. Apparently, the big Marvel death caught many viewers off guard during the screening and as previously noted, it sets a pretty dark tone for the rest of the movie. Additionally, the death reportedly sets the tone for the future of the MCU as a whole. The source had this to say.

"The beginning of Avengers: Infinity War features the death of a major Marvel character. Some fans will be expecting it, while others will be blindsided. It sets the tone for the rest of the movie - as well as the future of the MCU. It's good that the Russo Brothers are telling fans to be emotionally prepared for the film - because they'll definitely need to be. Whether you're expecting it or not, it's going to be big."

The source did not mention the name of the character, but there has been plenty of speculation about who it could be, which we won't go into here. But it should be pretty easy to figure out. As for the dark tone, we've been warned by the Russo Brothers and the trailers and TV spots have all echoed their thoughts. Plus, Marvel Studios boss Kevin Feige has promised that we'll learn the true power of Thanos within the first 5 minutes of Infinity War, which seems to be a pretty accurate statement.

Infinity War is Thanos' movie, according to the Russo Brothers. While we were going to get more of the villain's backstory in the original cut of the movie, the directing duo deemed it unnecessary in the end and had it cut out. The movie will still very much be the Mad Titan's though, and The Russo Brothers have also mentioned that we will even feel empathy for the character when we see him on the big screen. The line of thinking falls right in with what Thanos actor Josh Brolin has teased as well. Brolin has hinted that the villain was basically tossed aside for looking different and not recognized for his superior mind.

Related: Loki Is Officially Dead Confirms Infinity War Directors

There's a lot to take in with all the latest TV spots and promotional material for Infinity War, but there's still not a lot of information about the actual plot of the movie, which is pretty amazing at this point in time. Infinity War officially hits theaters next week, so all of the mysteries will be solved soon. But after this latest rumor, it might be a good idea to bring some extra tissues if you're a hardcore Marvel fan. You can read the original report at Screen Geek.