Starting in 2008 with Iron Man, the Marvel Cinematic Universe boasts 18 movies in 10 years, all of which have been box office successes. While the movies are vastly different, especially with the Guardians of the Galaxy movies which take place in a completely different part of the universe, all of them have connected back to each other to lead up to one thing.

For years, fans have seen the Infinity Stones weaved into the Marvel storyline, showing up in movies such as Captain America: The First Avenger, Guardians of the Galaxy, Doctor Strange, and many more, with glimpses at the cosmic giant who aspires to possess them all. That giant, Thanos, has the goal of using the Infinity Gauntlet to harness the power of all of the stones to wipe out half of the universe.

While we have only had a few short glimpses of Thanos, the climax of the mad titan’s venture will be front and center in Marvel’s upcoming Avengers: Infinity War, which releases on April 27, 2018, where we’ll get to see a culmination of all of the great Marvel heroes do everything they can to defend the Earth from Thanos at all costs.

To give you a clearer picture of what I mean by “all of the great Marvel heroes,” here is a list of those who are confirmed to be in the movie:

The film will feature the whole crew of heroes from Captain America: Civil War, including Team Stark’s Iron Man, War Machine, Black Widow, Vision, Black Panther, and Spider-Man as well as Team Cap’s Captain America, Falcon, Ant-Man, Scarlet Witch, and the Winter Soldier, who, according to a post credit scene from Black Panther, has been cured of the psychological struggles he endured after his experiences with Hydra and is back in fighting condition.

Speaking of Black Panther, some key characters from the recent installment will be returning for Infinity War. These include Shuri, the tech genius teenage sister of T’Challa, aka Black Panther, Okoye, a loyal Wakandan guard/warrior, and M’Baku, a tribal leader from Wakanda.

Also joining the film’s huge cast are the Guardians of the Galaxy; Star-Lord, Gamora, Groot, Rocket, Drax the Destroyer, Mantis, and Nebula. Doctor Strange and his sidekick/mentor Wong will also appear in the film, as well as everyone’s favorite villain turned good guy turned we’re not exactly sure which side he’s on, Loki.

Of course, with so many heroes uniting for this battle, there also exists the large possibility of losing a major character. In various comics related to the concept of an Infinity War, Thanos was eventually defeated, but with great loss; in one version, literally every Marvel hero was wiped out in the process. While this movie won’t take such an extreme path, as several actors are still under contract to do more Marvel movies, it is doubtful that the whole group will make it out alive.

One obvious possibility for a death is Vision. The reason is simple; Vision has the Mind Stone currently embedded in his forehead, so, if Thanos is to get all of the Infinity Stones, he would have to pry it out of Vision’s head, likely killing him in the process.

Another possibility is Gamora or Nebula. As they are both the daughters of Thanos, it isn’t implausible for there to be some sort of confrontation between them and their evil space tyrant father, who doesn’t seem like the kind of guy who would think twice about killing those who turned against him, even if they’re his own daughters.

Unfortunately, things don’t look so good for Loki either. In Avengers, Loki failed Thanos by his incapability to take over Earth and gain possession of the Tesseract, so Thanos already doesn’t like him. And if there’s one guy you definitely don’t want to be on the bad side of, its Thanos. Another point against Loki is the fact that he now possesses the Tesseract, meaning he would be a prime target for Thanos. The only way out for him seems to be the fact that he is arguably the MCU’s best villain to date, and killing him off may do the franchise more harm than good for the future.

As hard as it would be to lose Loki, some of the other potential deaths would be much more difficult to accept, wreaking havoc on Marvel’s core group. Its difficult to admit, but Iron Man and Captain America may not make it out alive. As seen in Civil War, the Avengers cannot continue to function as they are. The conflict between Stark and Cap effectively split the team into two, half of which ended up stranded as fugitives in hiding in the Wakandan jungle. Killing off either of these characters would give the Avengers a chance for a fresh start. And both of them have gained deeply rooted fanbases, so their deaths aren’t something we can just shake off and learn to live with, making either choice the huge plot-twist turning-turning point Marvel movies seem to lack so far. Even if they were to die, there are other suitable characters to take their places. In the case of a Tony Stark death, War Machine would be equipped to fill his suit, while the Winter Soldier is equally qualified to serve as the new Captain America figure if Steve Rogers didn’t make it out.

As before stated, the main focus of Infinity War is the Infinity Stones. In the words of The Collector, “Before creation itself, there were six singularities. Then the universe exploded into existence, and the remnants of these systems were forged into concentrated ingots… Infinity Stones.” The Infinity Stones are immensely powerful objects, each with their own unique characteristics and abilities, that can combine their power to create a nearly unstoppable force. This aspect of them is what appeals to Thanos, as he wants to gather them all in the Infinity Gauntlet and use their power to easily accomplish his goal of wiping out half the universe.

The Infinity Stones include the stones of Reality, Mind, Time, Space, Power, and Soul. The first Infinity Stone, the Reality Stone, takes the unconventional appearance of a red liquid substance called the Aether, and first appeared in Thor: The Dark World when it temporarily resided in the body of Jane Foster. The Reality Stone’s immense power allows the holder to distort reality, altering the laws of physics or raising the dead, even going as far as creating an entire alternate reality on a universal scale when used with the combined power of the other Infinity Stones. Currently, the Reality Stone is in the possession of the Collector, who received it from the Asgardians along with the task of keeping it safe.

The yellow Infinity Stone, the Mind Stone, was formerly kept in Loki’s scepter. As demonstrated while in Loki’s possession, the Mind Stone grants its holder the ability to control the minds of others. It is also said to increase the intelligence of its holder and was used to grant powers to Wanda and Pietro Maximoff, aka Scarlet Witch and Quicksilver, via Hydra experiments. The Mind Stone is currently held in Vision’s forehead.

Taking on a green color, the Time Stone made its MCU debut in the movie Doctor Strange, in which it is held in the Eye of Agamotto. The Time Stone gives its holder control over the flow of time; it can be used to go back in time, speed up the passage of time, and create a time loop. As a weapon, it can be used to trap an enemy in an endless time loop. At its full power, when combined with the other stones, the Time Stone can give its holder simultaneous existence in every point in time. The Time Stone still resides in the Eye of Agamotto.

The first Infinity Stone to appear in the MCU, the blue Space Stone is contained in the Tesseract. It is capable creating infinite energy and imitates teleportation, allowing the holder to create wormholes to other dimensions and parts of the universe be instantaneously transported to any location they desire. Taken from Odin’s Vault, the Space Stone is now in the hands of Loki.

Like the Space Stone, the purple Power Stone can create a virtually infinite power supply, meaning that besides the benefits it gives its holder it can also be used to limitlessly power any machine. It grants its holder access to all the power that ever was and ever will be, giving them unlimited strength and stamina as well as invincibility and the ability to imitate almost any physical superhuman ability. The Power Stone’s presence in the MCU is limited so far to Guardians of the Galaxy, and it is currently in the possession of the Nova Corps.

The only Infinity Stone left is the Soul Stone. The most mysterious of the group, the Soul Stone’s wide range of capabilities includes trapping souls in a world that exists entirely within itself, providing its holder with access to the memories and abilities of those trapped within it, and searching another’s soul to reveal information. However, we don’t know how much of this will spill over into the cinematic universe as the Soul Stone has yet to make its MCU debut. Which brings up another interesting point; while each of the other five stones have appeared throughout the movies and currently have a definite location, no one knows the whereabouts of the Soul Stone. Fans had theorized that it would appear in Thor: Ragnarok, likely in some important Asgardian figure such as behind Odin’s eyepatch or embedded within Mjolnir. When it failed to show up here, speculations were made that it would show up in Black Panther. This idea also came to nothing, so the Soul Stone now must appear in Infinity War itself. As it hasn’t been spotted in the trailers, some believe it will take the form of the giant orange planet seen in the trailer, since there doesn’t appear to be another logical reason for going to this planet. Outlandish though it may seem, the idea of an Infinity Stone taking the form of a planet isn’t completely unrealistic, as once in the comics the Power Stone grew to the size of a mountain.

Aside from the missing Soul Stone, one of the biggest mysteries surrounding Infinity War is Hawkeye. While directors Anthony and Joe Russo have confirmed the archer will be in the movie, he has yet to appear in any of the promotional material. Thus, with no leads to go off of, fans have had to generate their own theories about Hawkeye’s role in the upcoming film.

One such theory, suggested by Nerdist, is that Hawkeye was replaced by a Skrull. (For those of you who are unfamiliar with Skrulls, they are an evil alien race of shapeshifters). The site reasons that Hawkeye could have been switched with a Skrull back in Avengers, when he was under Loki’s mind control. If this were the case, Hawkeye’s storyline may be his efforts to escape Skrull captivity, which would explain his absence from his fellow heroes.

Another potential explanation is that he has become a villain. His absence from the trailers if this were the case would easily be explained by the fact that revealing him as a villain would be a huge spoiler, one that Marvel wouldn’t want to give away in the trailers. This theory is also backed by the fact that in Avengers he was the one Loki chose to control, which may suggest that Loki already saw a bit of villainy in him early on.

No matter where Hawkeye shows up, his role is sure to be a huge shocker, and the mystery has helped to build much excitement for the already highly anticipated Avengers: Infinity War. With the plethora of heroes joining forces, no one will leave the theater disappointed (unless, of course, Tony Stark dies, in which case I will be one of many unhappy fans).