Captain America screenwriter Christopher Markus has jokingly revealed the main reason he returned to pen Avengers: Infinity War was because of Red Skull. Markus, along with frequent co-writer Stephen McFeely, wrote Infinity War and its sequel, Avengers: Endgame. The Red Skull returns as the keeper of the Soul Stone on the planet Vormir, making his first appearance in the Marvel Cinematic Universe since he disappeared after the events of Captain America: The First Avenger.

The Red Skull made his MCU debut in Captain America: The First Avenger, played by Hugo Weaving. His character is the founder of the evil organization known as Hydra, which has played a significant role in several MCU films. In the climax of the film, the Red Skull appears to be consumed by the Tesseract, which is later revealed to contain one of the precious Infinity Stones. Following the events of the movie, the iconic comic book villain wasn't heard from again, though that didn't stop fan speculation about how he could return. In fact, before Captain America: The Winter Soldier's release, there was a theory making the rounds claiming Robert Redford's Alexander Pierce could be Red Skull in disguise. However, that theory was quickly disproven once the film hit theaters, causing fans to wonder if the character would ever reappear.

Related: How Red Skull Knew About The Soul Stone And Its Rules

Avengers: Infinity War co-writer Christopher Markus (via ComicBook) jokingly revealed he only returned to pen the blockbuster film because of Red Skull. Markus shared this piece of information during a quarantine watch party for the film. When discussing Red Skull's return in the movie, he states, "Bringing him back was the whole reason I agreed to do this movie. Well, that and all the other reasons. But to get a chance to bring back the bad guy from our first Marvel movie and use him in the wrap-up was too satisfying not to do." The full Twitter post is below.

Markus and co-writer Stephen McFeely have been integral players in the MCU's success. The dynamic duo has written numerous films in the Marvel canon, notably all three Captain America films, Thor: The Dark World and the last two Avengers films, which brought the Infinity Saga to its explosive conclusion. Markus and McFeely also created Marvel's Agent Carter television show for ABC, which centered on Hayley Atwell's Peggy Carter. She's Steve Rogers' famed love interest and S.H.I.E.L.D. agent, who also makes an appearance in Avengers: Endgame. There's also a chance she'll return to Agents of S.H.I.E.L.D. for its 7th and final season on the network.

Since lending their talents to the first Captain America film, Markus and McFeely have had a firm grasp on the MCU's superheroes, fleshing them all out in wonderful ways. Their work on both Avengers: Infinity War and Endgame was truly impressive, weaving together a massive story that brought the Infinity Saga to a close in spectacular and heartbreaking fashion. It's hard to blame Markus for feeling particularly drawn to writing the film due to the return of Red Skull. In a beautiful way, it brought Captain America's story full circle as he made his graceful exit from the MCU. Though it's fair to assume Markus and McFeely could play a role in future Marvel films, fans can still enjoy their work and the return of Red Skull in Avengers: Infinity War.

More: Why Marvel's Red Skull Could Never Get The Soul Stone

Source: Christopher Markus/ComicBook