In the mystical city of Kathmandu, a group of sorcerers, led by Kaecilius, invades the sacred Kamar-Taj enclave. They kill the librarian and steal powerful pages from a book belonging to the revered Ancient One.
In New York City, we meet Dr. Stephen Strange, a brilliant but arrogant neurosurgeon. A car accident shatters his hands, and he desperately seeks unconventional ways to heal them. He learns of Kamar-Taj and is introduced to sorcerer Mordo and the Ancient One.
Strange learns mystical arts, including the astral plane and the Mirror Dimension. The Ancient One agrees to mentor him, despite his arrogance reminiscent of Kaecilius.
Under the guidance of the Ancient One and Mordo, Strange studies ancient texts and discovers Earth's protection against interdimensional threats through three Sanctums. Meanwhile, Pangborn uses his newfound power for personal gain.
Kaecilius uses the stolen pages to commune with Dormammu, endangering Earth. He attacks Sanctums, killing guardians. Strange defends the New York Sanctum but is injured and saved by Dr. Palmer.
After a battle in the Mirror Dimension, the Ancient One is mortally wounded. She tells Strange and Mordo to unite to defeat Kaecilius. In Hong Kong, they find devastation. Strange has to decide which kind of sorcerer he wants to be to defeat Dormammu and Keacilius.