The movie opens furiously with a battle between a group of magicians and a mystic monster, rampaging in New York. The magicians are able to beat the beast, but not without Dr. Stephen Strange taking a glimpse of the fight, which is most unlikely, because the magicians tried to hide their tracks.We then learn that Stephen Strange is one of the most brilliant neurologists, however, he also appears to be one of the most selfish. After a colleague asks for his opinion on a children, having nightmares and finally ending up in a coma, he's able to see what the kid sees: An inflamed head what appears to be another mystic being (Dormammu). A lot of other children suffer from the same "disease".Strange isn't able to concentrate after this incident and as a result he drives his car over a bridge, leaving him with a serious injury. After the accident, he's no longer able to use his hands, making it impossible for him to operate.He now travels the world in search of a cure, but all efforts turn out to be unsuccessful. Strange is about to bring his life to an end, but only then the magician Wong promises him that he'll find a cure in an ancient temple in Tibet; home to the very group of magicians that fought the beast in the opening sequence, which is led by the Ancient One. Strange makes his way to Tibet where the Ancient One tells him that his biggest problem is actually he himself and he should rather seek a healing for his soul than for his physical needs. We then learn what caused Strange to become such a selfish person: In his past, his sister suffered from a strange disease and all other doctors didn't leave Strange with a promising result, so he decided to operate his sister himself. During the complicated operation - which might have been to hard for a young Dr. Strange that just earned his degree - his sister dies, leaving Strange with self-reproaches that still trouble him.After almost giving up his training, Dr. Strange overcomes his self-reproaches and finally gets a grip on the ancient magics. During the time of his training, Dormammu, the mystic being that wants to rule the world, sends one of his beasts after another to Earth in order to open a gate in the Sanctum Sanctorum, gateway to millions of different dimensions, including the dark dimension in which Dormammu is locked.Mordo, another promising magician, doesn't listen to the Ancient Ones advice and as a result, more magicians from the temple get killed defeating the Sanctum Sanctorum. The Ancient Ones then tells him that he'll never become Sorcerer Supreme, the leader of the group of magicians and therefore most powerful of all magicians. Instead, someone who doesn't want to become Sorcerer Supreme will be awarded with the burden and Mordos task is to actually train him. Mordo, realising that Strange is supposed to become Sorcerer Supreme, is close to killing Strange during the training, but Wong interferes.After being introduced to the Sanctum Sanctorum and touching the mystic barrier that holds back Dormammu, Strange realises that the disease which causes the children to fall into a coma is actually a result of Dormammus works. Strange then enters the hospital, trying to free the children from Dormammus influence. Mordo joined him, but only to offer Dormammu his services and join his side.In the following fight, the Ancient One falls to Dormammus creatures, but not before he was able to pass the Eye of Agamotto to Wong. Meanwhile, Wong tries to take on Mordo, while Strange is busy with Dormammu himself. Mordo is about to kill Wong, but Strange rescues his fellow magician. Wong passes the Eye of Agamotto on to Strange and tells him that he's now the Sorcerer Supreme. Dr. Strange accepts reluctantly and then faces Dormammu for the final battle.Dormammu can steal the Eye of Agamotto and open a gateway to his dimension, releasing plenty of demons to our dimension. Dr. Strange then gets the Eye bag and uses its power to absorb Dormammus mystic energies, defeating him this way.Wong then joins strange to continue their new life as mystic protectors of Earth, trying to recruit new magicians and banning the demons from our dimension.