“Doctor Strange in the Multiverse of Madness” follows Dr. Stephen Strange (Benedict Cumberbatch) as he navigates the chaos of the Multiverse to protect a teenager named America Chavez (Xochitl Gomez), who has the power to travel between universes. The film opens with Strange experiencing a premonition of America being chased by a demon. Later, during the wedding of his former lover, Christine Palmer (Rachel McAdams), a monster attacks, seeking America.
Strange seeks help from Wanda Maximoff (Elizabeth Olsen), only to discover she is the one pursuing America, hoping to use her powers to find a universe where her children are alive. Wanda, corrupted by the Darkhold, a book of dark magic, becomes the film’s antagonist.
Strange and America escape to an alternate universe, Earth-838, where they encounter the Illuminati, a group that includes an alternate version of Strange. The Illuminati are ultimately killed by Wanda in her quest for America’s power.
In a climactic battle, Strange, America, Wong (Benedict Wong), and the spirit of the alternate Strange confront Wanda. Wanda’s children in the alternate universe reject her, leading her to realize the error of her ways. She sacrifices herself to destroy the Darkhold across all universes, preventing further catastrophe.
The film concludes with America starting her training as a sorceress at Kamar-Taj, while Strange develops a third eye, a consequence of his brief use of the Darkhold. Despite the victory, the ending suggests that Strange’s encounter with dark magic will have lasting repercussions.