It has recently been confirmed by Kevin Feige that Doctor Strange will definitely be getting a sequel. This should not come as a surprise to anyone, as the 2016 release was a fun, quirky entry into the MCU, making just short of $700 million, and Benedict Cumberbatch has made the character a fan favourite through appearances in Doctor Strange, Thor Ragnarok, and Infinity War.
There is the small matter, however, of the Doctor's untimely demise at the hands of Thanos. When The Mad Titan snapped his gauntleted fingers, the Sorcerer Supreme bit the dust along with half of the entire universe.
When you consider the heroes that were lost, it was always going to be hard believe they would all stay gone. Not only is the immensely popular Black Panther all but guaranteed a sequel, Spider-Man and Guardians of the Galaxy sequels were already announced before Infinity War's release.
Now that Doctor Strange has joined this list, we know that he will be returning to our screens. The only question left then, is how?
The Quantum Realm was first seen in Ant-Man in 2015 and will be delved into deeper in Ant-Man and The Wasp. As seen when the titular hero found himself floating through the Quantum Realm, the laws of time and space (and who knows what else) are not what they are in our dimension.
This is something that The Avengers can use to their advantage if they, with the help of Michelle Pfeiffer's Janet Van Dyne as a guide, can manipulate it to take them back in time. Set pictures from the untitled Avengers 4 that show Paul Rudd suited up in past scenes like The Battle of New York, with clean-shaven Chris Evans, suggest that this course of action is incredibly likely.
Should the heroes go back in time to before the snap and alter the course of history, they could prevent Thanos from ever assembling all the stones in the first place. Since The Battle of New York is specifically where we see Lang return to, it could have something to do with either The Tesseract or Loki's Sceptre. Alternatively, it could be simply to warn Cap and Iron Man about The Mad Titan, not unlike The Flash in Dawn of Justice, but better.
Either way, if successful, Ant-Man could be the one to save half the universe from dissolving, including Doctor Strange.