Marvel Studios’ “What If…?” shakes up the classic films in the Marvel Cinematic Universe by asking one simple question. Presented and narrated by an omnipotent being known as “The Watcher” (voiced by Jeffrey Wright), each episode of the animated spinoff showcases different “what if?” scenarios based on different iconic moments from the MCU. The anthology series features most of the live-action cast reprising their roles. Generally, each episode will have one slight difference from the original film that allows its premise to take place.

The show’s first episode, “What if Peggy Carter was the First Avenger?” twists the origin of Steve Rogers’ Captain America, instead opting to give Peggy Carter (voiced by Hayley Atwell) the super-soldier serum. A small change from the original timeline leaves Steve Rogers (voiced by Josh Keaton) injured and unable to undergo his life-changing procedure. Peggy instead opts to take the serum in Steve’s place, beginning the episode’s premise.

Now christened as Captain Carter, Peggy fills the role that Steve Rogers’ Captain America filled in the original timeline. While Steve isn’t Captain America in this reality, he inadvertently becomes the first Iron Man. Wearing a suit of armor built for him by Howard Stark (voiced by Dominic Cooper), the so-called “Hydra-Stomper” aides Captain Carter on her missions in fighting Hydra. During their final stand against Hydra, Captain Carter forces a multi-dimensional monster (theorized by fans to be Shuma-Gorath) into a trans-dimensional portal. The episode ends with Peggy Carter being transported into the modern-day, much to the surprise of Nick Fury (voiced by Samuel L. Jackson) and Hawkeye (voiced by Jeremy Renner).

“What If…?’s” second episode: “What if T’Challa was Star-Lord?” twists the Guardian of the Galaxy leader’s origin. In this reality, Yondu (voiced by Michael Rooker) delegates Peter Quill’s abduction to Kraglin (voiced by Sean Gunn) and Taserface (voiced by Chris Sullivan) instead of personally overseeing it. The two Ravagers get confused and instead abduct a young T’Challa (voiced posthumously by Chadwick Boseman) from Wakanda. Having an interest in exploring the universe, the young Wakandan prince is adopted by Yondu, and so begins his time as Star-Lord.

As Star-Lord, T’Challa manages to be much more successful, not only as a Ravager but also in situations that daunted Peter Quill. He even manages to get the former Mad Titan, Thanos (voiced by Josh Brolin), to join the Ravagers. The episode’s plot involves T’Challa and the Ravagers in a heist as they attempt to steal from the Collector (voiced by Benicio Del Toro). And while they are successful in their heist, the end of the world looms over the horizon. The episode ends with a stinger as Ego (voiced by Kurt Russell) reunites with Peter Quill (voiced by Brian T. Delaney), preparing to tell Peter of his Celestial heritage and plans for galactic domination.

“What If The World Lost its Mightiest Heroes?”, the third episode, presents its concept as a murder mystery. As Nick Fury attempts to form the Avengers, they are picked off one-by-one by a mysterious killer. Tony Stark (voiced by Mick Wingert) is accidentally murdered during the events of “Iron Man 2”. Thor is killed by Hawkeye during their confrontation in “Thor”, and the latter is believed to have killed himself in S.H.I.E.L.D. custody. Understanding that the killer is targeting Avengers Initiative candidates, Nick Fury tasks the Black Widow (voiced by Lake Bell) to protect Bruce Banner (voiced by Mark Ruffalo). She is unsuccessful, as the Hulk explodes during his confrontation with the military at Culver University. Black Widow is the last to be picked off, after learning a key detail of the assailant.

Having learned from Black Widow that the killer has ties with Hope Van Dyne, who in this timeline was a S.H.I.E.L.D. agent, Nick Fury goes to her burial place for answers. There, Hank Pym, now the Yellowjacket, reveals himself as the killer. Having been stricken with grief from his daughter’s loss, and frustrated at S.H.I.E.L.D.’s supposed carelessness, he vowed to destroy all of Nick Fury’s work – including the Avengers Initiative. A fight between the two ensues, in which Nick Fury comes out on top with the help of Loki (voiced by Tom Hiddleston). The episode ends with Nick Fury finding a frozen Captain America and Captain Marvel (voiced by Alexandria Daniels) returning to Earth to fight a Loki-spearheaded invasion.

“What If…?’s” fourth and most recent episode “What if Doctor Strange Lost His Heart Instead of His Hands?” changes the origin of Doctor Stephen Strange (voiced by Benedict Cumberbatch). In this timeline, instead of losing his hands’ motor skills, Dr. Strange loses his girlfriend Christine (voiced by Rachel McAdams). While the reason why he searches for help in the mystic arts is different, the events of the movie otherwise play out exactly the same, even right down to the famous “Dormammu, I’ve come to bargain!” scene. It’s after the film’s events that Dr. Strange uses the Eye of Agamotto to travel back in time to the night of Christine’s untimely death. It is there that it is revealed to him by the Ancient One (voiced by Tilda Swinton) that her death is a fixed point in time and that it would be impossible to save her without destroying their reality.

Rather than accept her death, Dr. Strange instead seeks knowledge from the Library of Cagliostro that he believes holds the answer. There he learns that in order to break a fixed point in time the spellcaster needs to hold immense power, in which the only way for Dr. Strange to obtain that level of power is through absorbing the power of other beings. Over time absorbing different mythological creatures, Dr. Strange becomes more powerful as he starts to become mad and lose his humanity. He goes back to the car crash to save Christine, in which he is successful in resurrecting her. While he was successful in saving her, her resurrection causes the fabric of reality to collapse. He pleads with The Watcher to help him, to punish him instead of the world for his arrogance. The Watcher states that he cannot help and that Supreme Strange should know better than to tamper with the timeline. The episode ends with Supreme Strange floating in the void, forever trapped and alone in his reality.

“What If…?” is currently streaming on Disney+. New episodes air every Wednesday.