Marvel's What If...? has been a surprising addition to the Marvel Cinematic Universe's lineup of shows, including unlikely scenarios that would have never made the cut in the live-action version. The first episode fittingly stars a change in the history of the First Avenger, Captain America.
The episode's premise is simple. Instead of Steve Rogers becoming a super soldier, Peggy Carter is the one who receives the serum. Known primarily as being Steve's love interest, Peggy gets to truly shine. The change has incredibly complicated ramifications, leading to unexpected consequences for many characters in the Marvel Cinematic Universe.
10 Peggy Doesn't Leave The Chamber Following Her Conversation With Erskine And Notices The Hydra Infiltrator
According to the Watcher--the observer narrating the whole series--the main decision that leads to the change in paths is Peggy standing up for herself in front of Erskine. When he asks her if she wouldn't be more comfortable in the viewing chamber, she chooses to stay to support Steve. She notices Heinz Kruger planting an explosive, and the Hydra Agent attacks early. In the chaos, Steve is shot, leaving him unable to go through with the experiment.
9 Abraham Erskine Is Killed By The Explosion But Chester Philips Is Shot In His Place
In the original universe, Heinz Kruger kills Abraham Erskine after the experiment is over, by shooting him. In What If...?, the sudden explosion takes out several people, including Erskine. However, Colonel Chester Philips, who plays a big role in Captain America: The First Avenger, gets shot by Kruger instead.
After Philips's death, Colonel John Flynn takes over the SSR, and his disrespectful and disparaging comments follow Peggy all throughout the episode. John Flynn never appears in Captain America: The First Avenger, but he does show up in the Marvel one-shot, Agent Carter.
8 Peggy Manages To Take Out Heinz Kruger
In Captain America: The First Avenger, Heinz Kruger first succeeds in making his escape. Peggy does wound him, but she is unable to keep him from driving away. It is up to the recently transformed Steve Rogers to stop the undercover Hydra agent. Steve chases Kruger on foot and manages to catch him before Kruger can leave New York. Kruger ends up committing suicide and destroying the stolen batch of the serum. In What If...?, Kruger never escapes, as Peggy shoots him before he ever leaves the facility.
7 Peggy Becomes A Super-Soldier Whereas Steve Stays The Skinny Kid From Brooklyn
Naturally, the biggest change--the one that leads to the events spiraling further away from the original course of history--is Peggy becoming a super soldier in Steve's stead. With Steve injured and the equipment in the facility heavily damaged, it becomes obvious to Peggy that Project Rebirth will be a failure if she doesn't do something.
She, therefore, chooses to take the serum herself, much to John Flynn's dismay. With all the serum going into Peggy's transformation, Steve remains the skinny kid from Brooklyn.
6 John Flynn's Sexism And Peggy's Initiative Inadvertently Shatter The Winter Soldier Storyline
Despite the success of the experiment, John Flynn is furious. In his sexist blindness, he refuses to see Peggy as a super soldier, considering her only a weak woman. Unlike Steve Rogers, who is used as a poster boy for the USO in The First Avenger, Peggy isn't deemed worthy of that. She is completely benched.
It turns out to be a good thing, as when news comes of the Red Skull's search for the Tesseract, she is able to intervene. At first, Peggy and Howard bring up their concerns with Flynn, but when he refuses to take them seriously, Peggy steps in herself. She retrieves the Tesseract without too much difficulty. The Red Skull never gets the chance to create his destructive weapons. Her capture of Zola also means there is no one in Hydra to experiment with the Super Soldier Serum, which completely shatters the Winter Soldier storyline.
5 Howard Stark Creates The Hydra Stomper Using The Tesseract
The Red Skull may have been robbed of the opportunity to exploit the Tesseract's technological potential, but Howard Stark isn't. In fact, he receives a big chance. In the original version of the MCU, he only gets to study the Tesseract much later, when he finds it while looking for Steve's crashed plane.
In What If...?, he uses it to create the Hydra Stomper, a highly advanced robot that is basically Iron Man Mark 1. Steve is chosen as the pilot. He and Peggy form a great team in taking down Hydra. Bucky's squad still gets rescued, only this time, there's no sign that he has been experimented on.
4 Bucky Barnes Never Falls From The Train But Steve Does
Like Steve Rogers's Captain America, Captain Carter leads an operation to investigate a train, though this time, it isn't in search of Zola. In the original, Bucky falls but survives due to Zola's experiments. In What if...?, Peggy grabs his arm as he slips, saving him. Bucky even makes a joking comment about almost losing his arm, an obvious easter egg referencing his alternate self.
The train trip still goes wrong, though. It turns out to be a trap, and Steve discovers it has been booby-trapped with explosives. He manages to warn the others just in time, but he and his Hydra Stomper are lost. Either way, this completely frees Bucky from his fate as Hydra's brainwashed assassin.
3 Red Skull Opens An Interdimensional Portal And Is Consumed By A Monster
Steve's fall originally makes viewers feel the Winter Soldier storyline may yet happen in some way, this time with Steve at its center. Things take an entirely different turn. Peggy and her team arrive at Castle de Krake, an important military stronghold in the Black Forest in Germany. There, they find Steve still alive and the Red Skull in possession of the Tesseract.
Perhaps because of Zola's loss, the Red Skull chooses to use the Tesseract to open an interdimensional portal instead of researching the technology further. He intends to summon a champion from a different dimension and he succeeds. As the portal opens, a tentacled monster emerges from within. The Red Skull cheers at its appearance, but his happiness is short-lived as he is soon eaten by the creature. This also creates a small change, because of his death, there is no one on Vormir to watch over the Soul Stone.
2 Peggy's Confrontation With Hydra's Summoned Creature May Have Unprecedented Ramifications
The mysterious summoned creature appears several times throughout What if...?. A similar monster shows up in Doctor Strange's Episode Four. There has been speculation that the creature is Shuma Gorath, a lesser-known villain from the comics. Shuma Gorath is a cosmic entity so powerful he can control dimensions and destroy realities. He rules Ancient Earth for many years before being defeated by the sorcerer Sise-Neg, and later, by Conan the Barbarian.
He reemerges again several times, and perhaps unsurprisingly, he is known as one of Doctor Strange's villains. Peggy manages to banish the creature at the end of the episode, but it seems unlikely that Shuma Gorath is actually dead. Still, his mere appearance, as well as his confrontation with Peggy, could have unprecedented consequences on the Multiverse, assuming she has damaged him enough to make a long-term difference.
1 Peggy Is Absorbed Into The Portal Leaving Steve Behind
Hydra's champion is a challenge, and to defeat him, Peggy leaps at him with a sword. In order to keep everyone safe, she finds herself forced to shove the entity back into the portal. She's dragged along with the creature and disappears inside, leaving Steve behind. Seventy years later, during an experiment with the Tesseract run by Director Fury, she reemerges from the opened portal, unchanged. Steve's fate is unknown. However, considering his state of health and the time period he lived in, one can assume he died much sooner.