The movie opens nearly 50 years ago in the early 80s as we watch a younger Doctor Strange turn away a young Victor von Doom. Afterwards Stephen Strange tends to the Sanctum and takes up the role of Sorcerer Supreme following Wong's death. Throughout the movie Stephen is forced into a mentor role when Wong's friend's son Mordo comes to stay in the Sanctum following his mother's death. Strange has to deal with a teenager while realizing his mistake when turning away Victor. Eventually an old student of Wong named Kaecilius returns to take up the role of Sorcerer Supreme that he thinks he is owed but after discovering Stephen was granted the title he grows jealous and it leads to a fight between sorcerers. Stephen wins the duel and Kaecilius is banished but this isn't the end of the story. Some time later when Mordo is a grown man Stephen plans to step down as Sorcerer Supreme and pass on the title to Mordo but Kaecilius returns and has remained young thanks to him staying in the Dark Realm for decades. The movie climaxes with Stephen and Mordo fighting Kaecilius which ends in Mordo's death and Stephen being trapped in the Dark Realm until some time a couple years prior to the present.
