How Doctor Strange in the Multiverse of Madness Sets up Marvel’s Biggest Storyline Of All Time

Warning: Full spoilers follow for Doctor Strange in the Multiverse of Madness.

While Doctor Strange in the Multiverse of Madness features cameos from a number of familiar faces, one of the most important new additions in this sequel isn’t a character at all, but a concept. The movie introduces MCU fans to the phenomenon known as Incursions. When two universes collide, everyone’s life hangs in the balance.

Now that the Marvel movie multiverse has been unlocked, we can expect to see Incursions play a role in many MCU stories to come. With that in mind, it’s a good idea to brush up on the history of Incursions at Marvel Comics and why this reveal could be the next step in setting up a Secret Wars movie.

The Marvel Multiverse: What Are Incursions?

The Marvel multiverse consists of many thousands of parallel universes, all coexisting in cosmic harmony but never directly interacting with one another. Or, at least, that’s how it’s supposed to work. Incursions happen when the fabric of one universe is breached by another, usually centered around two parallel versions of Earth. When a breach is formed, a chain reaction begins that will ultimately destroy both universes.

There are ways of stopping Incursions, but it’s never easy and rarely without an enormous cost. One of the only surefire solutions is to destroy one of the two Earths, sacrificing billions of lives so that trillions more can live.

The first time the Avengers encountered an Incursion, Captain America was able to use the Infinity Gauntlet to force the invading Earth back into its universe. However, the sheer amount of energy needed was so great it shattered five of the six Infinity Stones, forcing the team to resort to increasingly desperate solutions to stave off future Incursions. As Thanos once mused, the hardest choices require the strongest wills.

When a breach is formed, a chain reaction begins that will ultimately destroy both universes.

How the Incursions Lead to Secret Wars

The Incursion phenomenon is a major plot point in writer Jonathan Hickman’s Avengers and New Avengers comics. The MCU already drew from Hickman’s work when it came to depicting Thanos and the Black Order in Avengers: Infinity War, and it seems those stories are again coming into play in Phase 4.

Hickman’s New Avengers in particular revolved heavily around the Incursion problem. That series introduces a new incarnation of the Illuminati, which consists of Black Panther, Namor, Iron Man, Beast, Mister Fantastic and Doctor Strange. The group discovers that the number of Incursions in the multiverse is increasing exponentially over time. Before long, the Illuminati are forced to make some very difficult decisions about whether it’s morally justifiable to sacrifice a planet for the sake of two universes. And as you might imagine, the rest of the superhero community is none too thrilled to find out what’s been going on behind their backs.

Over the course of the two series, readers learn that the Incursions are the result of a massive war between the Beyonders (omnipotent aliens who dwell outside the multiverse) and a death cult led by the fanatical Rabum Alal (eventually revealed to be Doctor Doom). The Beyonders hope to use the Molecule Man of every universe as a collective bomb that will destroy all of reality in one fell swoop. Doom and his allies (including Earth-616’s Molecule Man) set about prematurely killing these Molecule Men to disrupt the Beyonders’ plans.

In the end, the Incursions increase to the point that only two universes are left standing – the regular Marvel Universe and the Ultimate Universe. That’s where 2015’s Secret Wars begins, chronicling the final chapter in Hickman’s grand Avengers saga.

In Secret Wars #1, the two universes are rocked by one, final Incursion, and both are destroyed in the end. But Doom proves to be the hero existence needs. With Molecule Man feeding him a constant stream of godlike power, Doom is able to create a single planet called Battleworld. Stitched together from fragments of dozens of shattered universes, Battleworld is the sole planet that still exists in the endless void that was the multiverse. Secret Wars is all about what happens when Doom crowns himself God Emperor of his new world, and how Marvel’s heroes make sense of what happened and seek a way to restore everything they lost.

Incursions in the MCU: What Happens Next?

Doctor Strange in the Multiverse of Madness is the first MCU movie to feature Incursions, but it likely won’t be the last. Everything we know about this phenomenon from the comics suggests this is a problem that will continue to grow in the multiverse. The film’s mid-credits scene, featuring the debut of Charlize Theron’s Clea, suggests Clea and Strange will be pooling their magical talents to stop future Incursions.

They may not be the only ones. There’s a good chance we’ll see Earth-616’s version of the Illuminati at some point in a future MCU project. Maybe they’ve been working behind the scenes all along, or maybe they come together for the first time now. But either way, the MCU could easily draw on the idea of the Illuminati banding together to deal with the Incursion threat.

The end goal is very likely a full-fledged Secret Wars movie inspired heavily by the 2015 comic. It’s easy to picture Incursions becoming a recurring plot element across a number of future movies, culminating in the end of the multiverse as we know it in Phase 5 or 6 of the MCU. The MCU could even repeat the two-part approach employed with Avengers: Infinity War and Endgame. The first movie could showcase the futile battle to preserve the last two remaining universes, and the second one could explore what survives in the aftermath.

This isn’t to say the MCU will adapt Secret Wars beat-for-beat. That’s never really been the approach of these movies in the past. One major difference is that Jonathan Majors’ Kang the Conqueror will probably play a big role in the MCU’s Secret Wars, whereas Kang is only a supporting character in the 1984 comic and doesn’t play a big part in the 2015 version. Thanks to Loki: Season 1, we know He Who Remains was responsible for eliminating the multiverse and preserving his “Sacred Timeline,” thus preventing his other selves from waging their destructive war across time and space.

Now that the multiverse is back, it stands to reason Kang is a key part of the puzzle that is Secret Wars. Kang may even be the source of the Incursions in the MCU, rather than the Beyonders. Or he could take the place of Doctor Doom in this version, as we have yet to meet the MCU’s Victor von Doom or his nemesis Reed Richards.

With Spider-Man: No Way Home also leaning into the multiverse, we have to wonder how much the Spider-Verse might factor into Marvel’s long-term plans. No Way Home teased the debut of the MCU’s Venom, and it’s worth remembering that Peter Parker first encountered the alien costume in the 1984 Secret Wars comic. Will we see Tom Holland don the black costume as part of the Secret Wars movie?

Do you think the MCU is building towards a Secret Wars movie? Will Doctor Doom or Kang the Conqueror be the last villain left standing? Let us know what you think in the comments below, and sound off in the poll about which upcoming MCU movie you’re most excited for:

Jesse is a mild-mannered staff writer for IGN. Allow him to lend a machete to your intellectual thicket by following @jschedeen on Twitter.