If you’re a major Marvel fan, you’ve surely spent your fair share of time binge-watching entries into the MCU, diving through the expanded universe of Disney+ programming for added lore and arguing with your friends about various hypotheticals within the canon of the multiverse. The original series What If…? explores many of these fan-favorite hypotheticals as the extraterrestrial Watcher takes viewers through bizarro timelines, outlining small changes that lead to massive ramifications. The third season premiered on Dec. 22, delivering new episodes daily through Dec. 29. According to the available info, we can expect to see new episodes centered on the Hulk fighting the Avengers, what would happen if the Watcher ceased to exist and even an examination of Howard The Duck’s love life.

Since it may have been a while since you’ve binge-watched the first two seasons of the beloved series, now seems like a great time to brush up on all of the mind-blowing alternate timelines explored by What If…? throughout the first two seasons. Luckily, we’ve got you covered, with a comprehensive look into each episode thus far. Though this is an anthology show, which generally doesn’t carry serialized narratives from one episode into the next, the MCU is intrinsically connected via multiple crossovers, so it’s always good to brush up before diving in for brand-new episodes. With no further preamble, let’s don our suits, shields and hammers to examine a full recap of Marvel’s What If…?.

What If… Our Beloved Characters Traded Places?

The very first episode of What If…? asks what would happen to our known MCU world if Peggy Carter were to become the first super soldier instead of Steve Rogers. In this timeline, Rogers is injured by Hydra spies before he can undergo the super soldier operation, causing S.H.I.E.L.D. scientists to pivot into working with the SSR. After Peggy takes the serum to gain super-human strength and agility, she is discriminated against by her boss for being a woman, but quickly rises through the ranks and establishes herself as Captain Carter. Howard Stark serves as Peggy’s man in the chair, creating otherworldly devices for her to use in battle, as she takes to combat alongside Steve Rogers.

By the end of the first episode, Peggy and Steve manage to best Red Skull in battle, though Peggy is sucked through a portal opened by the Tesseract. Decades later, the portal opens back up on Earth and Peggy emerges to meet Nick Fury in an almost 1:1 recreation of Captain America’s origin story.

Like the first episode, the following installment of What If…? sees two iconic MCU heroes trading places. In this one, the Ravagers who were sent to Earth to find Peter Quill mistakenly pick up a young Prince T’Challa from his home in Wakanda. By the time T’Challa grows into adulthood, his inherent charisma and charm turn the Ravagers into a morally upstanding band of intergalactic social workers. Even Thanos is charmed by T’Challa’s upbeat worldview, having eschewed his dreams of destroying the universe in favor of saving people. When the gang hears rumors about a cosmic artifact with dangerous ramifications and a genocidal madman’s hunt for the tool, they spring into action, determined to save the galaxy from certain doom.

Episodes 3 and 4 Center on Loss

Episode 3 of What If…? asks what would happen if the Avengers were to perish in battle, stripping the globe of its S.H.I.E.L.D. safety net. As Nick Fury attempts to staff his Avengers initiative with Bruce Banner, Tony Stark, Clint Barton, Thor and others, they each mysteriously die just before they can be reached. Thor’s death prompts an Asgardian invasion, wherein Nick Fury and Loki strike up a partnership. Together, the two discover that Hank Pym has been systematically destroying the would-be Avengers using his shrinking technology, in an act of vengeance following his daughter’s death. Fury and Loki defeat Pym in battle and have him sent away to Asgard to face trial before Loki pulls a classic double cross and attempts to take over the world. The final moments of the episode see Fury thawing Steve Rogers out of glacial ice, and summoning Carol Danvers to defeat Loki.

The fourth episode is where things become exceptionally dark. In the opening scene, Dr. Stephen Strange gets into a car accident, killing his beloved girlfriend Christine Palmer. Burdened with grief, Strange seeks answers from spiritual leaders and scientists alike, before turning to the dark corners of the mystic arts. Eventually, he spawns the Eye of Agamotto and uses it to manipulate time. Unfortunately, Strange learns that his partner’s passing is an absolute point in his universe, meaning it cannot be undone even with time travel. Unable to move on, Strange absorbs the power of the Dark Dimension and becomes an all-powerful being named Strange Supreme. He resurrects Palmer, though doing so disintegrates the fabric of the universe. Strange Supreme begs the Watcher for assistance, though the Watcher explains that his role is simply to take in information, and never to intervene.

‘What If… Zombies?’ Is a Season 1 Highlight

Episode 5 of What If…? sees the world’s mightiest heroes battling it out against a zombie apocalypse, wrought by Hank Pym and Janet van Dyne’s meddling in the Quantum Realm. By the time the pair realize what they’ve done, the virus has already spread across the globe, causing figures such as Iron Man, Thanos, Wanda Maximoff and more to become walking corpses, equipped with the dangerous skillset and strength of their living counterparts. After a group of survivors learns that a possible cure may be found at a military training facility in New Jersey, Peter Parker, Scott Lang and T’Challa battle their way across hordes of zombies to get there. The episode sees a wide array of incredible action set-pieces, including one climactic fight between the Incredible Hulk and a zombified Scarlett Witch, before ending on a massive cliffhanger.

Just a few months after “What If… Zombies” was released, Marvel announced that they’d be expanding on this particular episode with a spinoff series titled Marvel Zombies. This made sense, as the episode managed to wow audiences far and wide, and completely dominate social media discussion of the series. The show is expected to premiere in October 2025, with most of the mainline MCU cast members returning to voice their original roles.

Episodes 6 and 7 Take On Unlikely Partnerships

Episode 6 of What If…? takes us all the way back to the origins of the MCU, as Tony Stark is captured by the Ten Rings in Afghanistan. This time, instead of building his classic Mach 1 Iron Man suit, Tony escapes when Killmonger storms the compound and springs him from captivity. Killmonger goes on to tell Stark all about his partner Obadiah’s plan to overthrow his company and puts a plan in motion to connect Rhodey with Vibranium dealers out of Wakanda. Right when it seems like Stark industries is saved, Killmonger double-crosses everyone involved, killing T’Challa, Stark and Rhodes, and jet-setting to Wakanda to take the throne as the new Black Panther. The episode ends on a cliffhanger, as the United States and Wakanda are on the verge of war and Shuri meets with Pepper Potts to expose the horrifying truth about Killmonger.

The following episode sees a timeline where Odin discovers and returns Loki to his biological parents during infancy, rather than raising him as his own. This leaves Thor to grow up as an only child, turning him into a hard-partying playboy who uses planet Earth as an Airbnb for intergalactic ragers. Unfortunately, Thor winds up doing a lot of collateral damage to Earth in the process, causing S.H.I.E.L.D. operatives to call in the cavalry. Carol Danvers eventually arrives to dispatch the Asgardian, though their battle ultimately does more harm to the surrounding area than good. By the time their epic showdown concludes, Ultron has apparently been able to collect all six Infinity Stones, signaling the end of all life as we know it. The episode ends on a cliffhanger, setting the scene for the final two episodes of season one.

Season 1 of ‘What If…?’ Shows That the Watcher Cares More Than He Lets On

The penultimate episode of What If…? season one continues the storyline of the previous episode by flashing back to Ultron’s creation. Just like the main MCU timeline, Tony Stark built Ultron as a safety net for the world, only for the AI automaton to immediately turn on humanity. In this timeline Ultron takes over the body of Vision and collects all of the Infinity Stones, making quick work of foes like Thanos along the way. As Ultron launches an army of drones to wipe out all life in the universe, he becomes privy to the existence of the Watcher and departs his timeline to destroy the entire multiverse. Having never encountered such an existential threat, the Watcher returns to the Strange Supreme universe of episode four and asks the grieving Doctor to assist him in putting an end to Ultron’s reign of terror.

In the season finale, the Watcher recruits Strange Supreme, Captain Carter, Only-Child Thor, Black Panther Killmonger, Star-Lord T’Challa, and a particularly powerful Gamora variant to dispatch Ultron. He names this makeshift team of previously highlighted heroes the Guardians of the Multiverse and sends them all to the timeline where Ultron was first created. After tracking down a bereft Natasha Romanoff, the gang can take control of Ultron’s body and eviscerate his hive-mind from within. True to his villainous nature, Killmonger betrays the team and attempts to steal the stones for himself. Before he can do so, Strange locks Killmonger and Ultron inside a pocket dimension and agrees to live out the rest of his days watching over them as a warden. Having already interfered enough, the Watcher thanks his team and sends them back to their respective homes.

Season 2 Brings Back the Guardians of the Galaxy

The first episodes of What If…? season two bring us back to the Guardians of the Galaxy franchise, by focussing on characters like Nebula and Peter Quill. The premiere sees Nebula taking up arms against her former employer, Ronan the Accuser, after the latter successfully pulls off a coup on Nebula’s father, Thanos. Ronan goes on to terrorize the galaxy, causing Xandar to seal itself off from the surrounding worlds. When Nebula discovers Yondu’s dead body, she uncovers a shocking conspiracy by Nova Prime to sell Xandar and its citizens out to Ronan and narrowly avoids being killed by Nova’s men. Nebula then puts together an even more rag-tag team than usual, with assistance from Groot, Miek, Korg and even Howard the Duck to defend Xandar against Nova and Ronan. The episode ends with the citizens of the planet hailing Nebula as a hero.

The following episode asks what would have happened if the Ravagers had honored their agreement with Ego, and delivered a young Peter Quill to his colonizing father. With no moral compass to guide Quill’s adolescence, he grows to do Ego’s bidding and returns to Earth with plans to destroy the planet. A team of make-shift Avengers including Peggy Carter, Howard Stark, Hank Pym, and King T’Chaka assemble to stop Quill, though they ultimately fail to contain him upon arrival. After chasing him down, the proto-Avengers see that Quill has returned to Missouri, to mourn at the site of his mother’s grave. This exposes Quill’s human side, allowing the team to convince him to fight back against Ego before it’s too late. With barely a moment to spare, Quill agrees and assists the others in destroying Ego’s avatar.

Happy Hogan Gets His Own Adventure

Avid watchers of the Marvel Cinematic Universe primarily know Happy Hogan as little more than Tony Stark’s right-hand man. Though he doesn’t have any superpowers, his assistance has been invaluable throughout the years, especially as Stark steps away from his business to punch bad guys into next week. Season 2 episode three of What If…? flips this dynamic on its head, however, as Happy gets his own Christmas adventure, stopping the forces of evil while Stark and company enjoy a brief respite from the action.

In the episode, Happy Hogan oversees security measures at an Avengers Tower holiday party, when he catches wind of a terrorist plot to steal Stark tech. While fumbling with the villains, Hogan is accidentally injected with a sample of Bruce Banner’s blood, turning him into a Hulk-like monster. Since the Avengers are out of town on holiday and J.A.R.V.I.S.’s AI is temporarily inactive, Hulk Hogan decides to take on the threat all by himself. Thanks to his newfound powers, Happy is able to smash the terrorist cell with relative ease, protect the Stark tech and save Christmas. By the time the Avengers hear about the issue, it’s already been resolved, leaving them to praise Happy for his hard work.

Episodes 4 and 5 of Season 2 Rewrite Avengers History

'What If...?' Recap pictured: 'What If...?'
Disney+/Marvel Studios

Episode four picks up right as Tony Stark defeats the Chitauri invasion of New York in 2012. Unfortunately, this timeline’s Stark is not able to return through the wormhole, leaving him stranded in outer space. Before he can die of exposure, he is picked up and dropped off on Sakaar, where he is selected to compete in race trials by the Grandmaster. While on Sakaar, Stark is accosted by Gamora, who was sent by Thanos to kill him for interfering in the invasion. Before she can kill her target, Gamora and Stark are both thrown into the dungeon, where they meet the likes of Korg and Valkyrie. In a desperate bid to escape, Strark demands the Grandmaster race him for the title of King of Sakaar and narrowly wins. In the end, Valkyrie becomes the planet’s new leader, while Stark and Gamora each set out on their own paths.

Episode five returns to the timeline where Captain Carter becomes the first super soldier, and sees her mowing down Hydra soldiers in search of her missing compatriot Steve Rogers. With the help of Natasha Romanoff, Carter locates Steve and learns that he was brainwashed and made to pilot the Hydra Stomper mech-suit. The women (along with Bucky Barnes) attempt to save Steve though they learn that the suit is the only thing keeping him alive. In a desperate bid to save their friend, the trio invade the Red Room where Hydra is headquartered and find themselves ambushed by soldiers, assassins and spies. Eventually, Steve manages to see through the fog, and sacrifices himself to destroy the Red Room, along with all of its brainwashing technology. The end of the episode sees Captain Carter sucked through a portal into another timeline, setting up the final two episodes of the season.

Season 2 Sees Trouble in Asgard

Season two episode six of What If…? sees Surtur destroying Asgard during Ragnarok, which sends the Tesseract hurtling toward Earth and landing in a pre-colonial America. The Tesseract lands in a small lake, turning the entire body of water into a portal to another dimension. Over the years, multiple people have gone missing after diving into the lake, including one Native American woman from the Mohawk tribe named Kahhori. After going through the portal, Kahhori begins honing a set of newfound powers, which have life-altering impacts on her surroundings. She can use these powers for good, driving away attacking Spanish Conquistadors before the episode ends on a cliffhanger. In the final moments, Strange Supreme appears and demands that Kahhori follow him into another timeline.

The following episode returns to Asgard and opens on Odin’s orders to strip Hela of her powers and banish her to Earth. Hela lands, powerless, in medieval China, where she is recruited to join the Ten Rings by Xu Wenwu, the organization’s founder. At first, Hela attempts to steal the rings for herself, though she ultimately comes to relinquish her lust for power, and searches for strength within. Years later, Heimdall reports that he has lost track of Hela entirely, causing Odin to lead an army to Earth to track her down. Hela and Wenwu join forces to fight back against Odin, and eventually best him in battle, leaving the god no choice but to relinquish his throne to Hela. In the end, Hela claims her place as Queen of Asgard and begins working alongside Wenwu and Gamora to stop Thanos from destroying the universe.

Another Major Crossover Event Wraps the Last Installment

The penultimate episode of the season offers the prompt, “What If… the Avengers Assembled in 1602?” It picks up after Captain Carter arrives in an Elizabethan era world, and becomes prompted to save the realm from a temporal anomaly. After communing with Tony Stark, Carter realizes that a time-displaced individual is causing the fabric of this universe to implode, which could threaten the entire multiverse. Carter then interacts with the likes of Wanda Merlin, Sir Nicholas Fury and King Thor, who each demand that she assist them in saving their timeline before it’s too late. Eventually, Carter can steal the time stone from Thor, and hand it off to Stark to identify the threat. Together, they learn that this universe’s Steve Rogers was transported here in error, after a gruesome battle against Thanos in another reality. Carter manages to rescue Rogers and send him home, before she is accosted by Strange Supreme.

The final episode of the series thus far sees Captain Carter following Strange Supreme to his Sanctum Infinitum, where he outlines the rules of the known multiverse. As Strange explains, he’s made it his mission to capture and watch over temporal beings who endanger the multiverse, ever since his world was destroyed by his own attempts to save Christine Palmer. Recognizing Carter’s timeline-hopping abilities, Strange asks her for assistance in tracking down a timeline killer named Kahhori, who wields the powers of the Tesseract. Eventually, Carter does locate Kahhori, though the latter informs her that Strange is not what he seems. Apparently, Strange has been using timeline variants to feed a device called the Forge, which he plans to use to jumpstart his own universe again, in stark contrast to his own supposed ethical code.

When Strange attacks Kahhori, Carter opens up the pocket dimension of Strange’s timeline killers, revealing Black Panther Killmonger from season one. After a brief battle with Killmonger, Carter manages to snatch his Infinity Stones and uses them to defend herself against Strange Supreme. As the entire Forge collapses in the heat of the battle, Strange ultimately sacrifices himself, which rends him in twain and eliminates him from the known multiverse. Once more, the Watcher steps in to course correct, sending each respective individual back to their worlds. Before the credits roll on season two, Carter asks the Watcher to show her more fundamental truths of the multiverse, and the otherworldly being abides.