What if Peggy Carter took the super-solider serum that created Captain America instead?

That was the premise for the 33-minute first episode of the latest MCU show, What If...?, which retells the story of The First Avenger after the creation of the multiverse.

The highly-anticipated animated series deals with a completely different timeline that explores alternate possibilities that one single choice can bring about.

The premiere focuses on the origin of Captain America. But instead of Steve Rogers – reprised by Chris Evans – picking up the mantle, his long-time lover dons the shield after she chooses to stay and watch his procedure.

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All of this is carefully observed by a mysterious alien observer, The Watcher, voiced by Jeffrey Wright.

But, what does this mean for the MCU? And how did Peggy's decision alter the course of events?

The year is 1942, and just like the events in Captain America: The first Avenger, Steve has been selected to be the world's first super-solder.

Narrated by the strange extraterrestrial entity, the episode jumps right to the Brooklyn native preparing for the procedure.

Yet, after Peggy, voiced by Hayley Atwell, chooses to stay, the experiment is botched when a spy from Hydra tries to steal the formula.

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The traitor ends up shooting Steve and the lab goes up in flames. After Peggy takes the bad guy down, she volunteers to take the serum in Steve's place. But because Peggy is a woman in very different times, her heroic effort is rebuffed by the new SSR leader, John Flynn.

Still, Agent Carter was never one to back down from a fight. So, the new and improved Peggy disobeys orders and ventures off to retrieve the Tesseract from Red Skull and rescue Bucky Barnes.

Of course, she succeeds, while Steve assists in a weaponized and armored "Hydra Stomper" suit built by Howard Stark with the Tesseract. But he is presumed dead after the team tries to stop a Hydra train that was booby-trapped with explosives. Heartbroken, Peggy and the rest of the team infiltrate Red Skull's castle, where Steve turns out to be alive and well.

But team are still too late, as Red Skull uses the Tesseract to open a portal and bring forth an interdimensional tentacled creature that ends up killing him. The ending shows Peggy sacrificing herself by entering the portal to push the creature back.

The super solider is last seen learning from the animated versions of Nick Fury, played by Samuel L. Jackson, and Clint Bart/Hawkeye, voiced by Jeremy Renner, that she's landed 70 years in the future.

In the end, The Watcher closes by eerily saying that he is "all-knowing," but can't interfere.

So, remember at the end of the Loki finale, when He Who Remains warned Loki and the variant Sylvie about the multiverse?

Obviously, he wasn't joking about their being different universes unleashed should he be killed.

Nice Job, Sylvie.

Still, the deed was necessary as it has opened a new door into the MCU, aptly setting the tone for what's to come.

Obviously, What If..? plays a key role in setting up the future releases Doctor Strange in the Multiverse of Madness and Spiderman: No Way From Home.

But to what extent is the question? Hopefully the next episode picks up the patch more.

What If...? certainly shows promise and is nicely setting Phase 4 apart from its predecessors.