It’s the reunion Ryan Reynolds has been trying to orchestrate for nearly a decade. One’s a motor-mouth, the other taciturn. They’re indestructible, though they both curse plenty when in the midst of fisticuffs. Deadpool and Wolverine, who appeared together in the much-maligned 2009 film X-Men Origins: Wolverine, are back together and hoping to make box office history. Reynolds and Hugh Jackman will star in Deadpool and Wolverine, out July 26.

Disney is betting big on these two heroes. Marvel Studios’ only movie debuting in 2024 is poised to become the highest-grossing R-rated movie in the history of cinema.

How, exactly, the two beloved superheroes found themselves sharing the screen again is a complicated tale involving the rights to the X-Men characters changing hands, Hugh Jackman’s 24-year history with the Wolverine character, and complicated plot mechanics involving the Marvel Cinematic Universe’s increasingly complex multiverse.

Here’s everything you need to know about Deadpool and Wolverine’s team-up and what it may mean for the future of the MCU.

Wolverine and Deadpool have a long history in the comics

Wolverine and Deadpool have similar origin stories. Both received their powers (not totally willingly) via the Weapon X project. The shadowy group gave Logan (a.k.a. Wolverine) his Adamantium skeleton, and when Wade Wilson (a.k.a. Deadpool) was fighting cancer, they grafted Wolverine’s healing factor onto Deadpool’s DNA.

The fact that both characters can heal quickly from any wound also makes them ideal sparring partners. In the comics, Wolverine and Deadpool meet in 1994’s Wolverine #88. Deadpool is throwing a fit after failing to win his ex back from her new boyfriend, and Wolverine intervenes. The two insult and stab each other until everyone is tuckered out.

Deadpool and Wolverine have gone on to team-up or fight it out over the decades, in classic frenemies fashion.

They have appeared together onscreen once before, though it didn’t go well

Ryan Reynolds made his debut as the Merc with a Mouth in the much-pilloried X-Men Origins: Wolverine in 2009. In that film, the famously chatty Deadpool had his mouth sewn shut in an utterly bizarre creative zag from his comic book origins. Marvel fans didn’t love it.

The negative response to the movie motivated Reynolds to do justice to Deadpool in his own spinoff series. The actor has been on a (self-aware) apology tour ever since. In an end-credits scene for Deadpool 2, Deadpool actually travels back in time to murder the version of himself that starred in X-Men Origins. Expect similar fourth-wall breaking jokes in Deadpool and Wolverine.

Hugh Jackman wanted to reprise his role as Wolverine after Logan

Hugh Jackman initially said he was hanging up his claws after (spoiler alert) Wolverine died in 2017’s Logan. Jackman made his debut as Wolverine way back in the 2000’s X-Men, an seventeen years is a long time to maintain a superhero physique—though apparently not long enough.

Reynolds has been publicly begging for a Deadpool-Wolverine crossover since the first Deadpool debuted. And ultimately, Jackman couldn’t resist the allure of returning to his iconic character—and presumably the hefty paycheck offered for returning to the role.

“I didn’t miss it for a long time,” the actor told Variety. “And then, literally, it came to me one day as I was driving down to the beach. I knew I wanted to do this. I literally stopped the car, got out and called Ryan. He said, “Are you serious?” I said, “I’m serious.” And I hung up the phone.

Read More: Can Wolverine Die? What Could Kill Him?

Marvel Studios finally owns the rights to the X-Men

When Marvel Studios launched the MCU with Iron Man in 2008, they didn’t own the rights to some of Marvel Comics’ most popular characters—namely, the X-Men, the Fantastic Four, and Spider-Man. Disney acquired Marvel Studios and, over the years, has brokered deals to scoop up those famous characters. Disney completed its acquisition of 21st Century Fox in 2019 and took over the rights to both the Fantastic Four and X-Men from that studio. (Marvel Studios has been making Spider-Man movies in collaboration with Sony, which still owns the rights to Peter Parker.)

So far, Marvel has used the characters in the X-Men arsenal sparingly. Since Wanda Maximoff and her brother Pietro Maximoff were both X-Men and Avengers, versions of those characters existed both in Fox’s X-Men movies and in Disney’s Avengers films.

Disney made the crossover of the two universes official in WandaVision when the Fox version of Pietro (played by Evan Peters) showed up in Wanda’s mystical world even though the Disney version (played by Aaron Taylor-Johnson) had died in Avengers: Age of Ultron. (Audiences later found out Pietro’s resurrection was a fantasy of Wanda’s maxing.) Meanwhile, an alternate universe version of Patrick Stewart’s Professor X from the original Fox X-Men movies made a cameo in Disney’s Doctor Strange in the Multiverse of Madness.

Though Deadpool wouldn’t seem a natural fit for the House of Mouse—when the deal was announced, Reynolds posted a picture of Deadpool getting escorted out of Disneyland after trying to “blow the Matterhorn”—the MCU’s recent foray into multiversal storytelling afforded an exciting opportunity.

The multiverse can resurrect Wolverine

Nearly every MCU movie in the last five years has engaged with the concept of the multiverse. Shows like Loki and movies like Spider-Man: No Way Home established that there are parallel universes to our own, many of which contain alternate versions of the same superheroes. In some cases, those versions are played by the same actor (see: the different variants of Doctor Strange in Multiverse of Madness all played by Benedict Cumberbatch). Sometimes, they’re played by different actors (see: Tobey Maguire’s Spidey, Andrew Garfield’s Spidey, and Tom Holland’s Spidey all teaming up in No Way Home).

Despite Wolverine meeting his doom in Logan, the MCU can now easily resurrect him. A younger version of the character that has not yet died could be pulled into Deadpool’s universe, a la the long-dead Green Goblin popping up in Spider-Man: No Way Home. Trailers for the movie have already highlighted the Time Variance Authority, essentially the cops of the Marvel multiverse who played a major role on the Loki TV series. They will help both characters skip across the multiverse.

They’re two of the most successful cinematic superheroes ever

At a time when superheroes aren’t nearly as bankable as they used to be—movies like The Marvels and Aquaman and the Lost Kingdom disappointed at the box office in 2023—Disney is hoping that Wolverine and Deadpool can bring in the big bucks. And they probably will.

Despite both earning R ratings, the Deadpool movies have been big hits. The first movie holds the record for the biggest opening ever for an R-rated film. In total, Deadpool earned $782.8 million globally in 2016, and the 2018 sequel made $785.8 million globally.

Wolverine, meanwhile, has a long and successful history at the cinema. Hugh Jackman, after all, was the star of the many successful X-Men films that debuted throughout the 2000s and 2010s. X-Men: Days of Future Past, in which Jackman’s Wolverine travels through time to save the world, ranks only behind the two Deadpool movies at the worldwide box office at $747.8 million. The last solo Wolverine movie Logan, which also got an R rating, grossed $619.2 million worldwide.

Together, the two superheroes could make box office history. Currently, Deadpool and Wolverine is tracking at $160 million to $165 million domestically. If it reaches that goal, it will become the biggest opening for an R-rated movie ever.

Deadpool and Wolverine could usher new characters into the MCU

This movie is, presumably, full of cameos. Multiversal movies usually are. Just like Disney tried to surprise audiences with the appearance of the old Spider-Men in Spider-Man: No Way Home or with John Krasinski’s Mr. Fantastic in Multiverse of Madness, the studio is keeping the plot of Deadpool and Wolverine a secret.

Director Sean Levy recently told Entertainment Weekly, “We didn’t want any of the cameos or characters to be the story of the movie. But they are peppered in throughout. There’s a lot of characters. The internet is a delight of rumors about the multitude of character cameos that are in this movie. Some rumors are true, some are way off base.”