'Wicked' is a prequel to 'The Wizard of Oz.' Here's where it fits in the story's timeline.

• The new "Wicked" movie musical is a prequel to "The Wizard of Oz."
• Many characters established in "The Wizard of Oz" make appearances in the first film.
• Here's what to know about how the two stories overlap.

Spoilers ahead for "Wicked" movie and Broadway show

"Wicked" is a prequel to "The Wizard of Oz," but the story starts halfway through the original 1939 movie.

This may confuse some fans who tune into the new prequel, which premieres this week on the same day as another blockbuster heavyweight, "Gladiator II."

The 1939 film and other adaptations of Oz, like 1970s film 'The Wiz', are based on the original book by Frank L. Baum "The Wonderful Wizard of Oz," written in 1900.

The "Wicked" movie and Broadway show, however, are based on Gregory Maguire's 1995 revisionist novel "Wicked: The Life and Times of the Wicked Witch of the West."

Maguire's novel reframes the popular plot of the original book and 1939 movie "The Wizard of Oz" around the book's main villain, the Wicked Witch of the West. Elphaba, as she's christened by Maguire, is the hero of this rewriting.

The Broadway adaption of the book is a resounding success. Since its debut in 2005, "Wicked" has become the second-highest-grossing Broadway show, selling over a billion tickets.

Wicked begins after Elphaba's death

"Wicked" closely follows the musical's first act, which begins half way through the original plot of "The Wizard of Oz" film.

"The Wizard of Oz" starts when Dorothy Gale, her dog Toto, and her house are picked up by a tornado in Kansas and dropped in Oz, landing on and killing the Wicked Witch of the East.

Glinda the Good Witch gives Dorothy the Wicked Witch of the East's ruby shoes. The Wicked Witch of the West, the Witch of the East's sister, (also known as Elphaba) swears vengeance against Dorothy.

Later in the film, Dorothy must steal Elphaba's broom and deliver it to the Wizard of Oz, so the Wizard will transport her home to Kansas. Dorothy accidentally splashes water on the witch during the encounter.

The witch melts and eventually dies, allowing Dorothy to complete her mission to retrieve Elphaba's broom for the Wizard.

This moment is where "Wicked" begins.

The movie's opening scene is set in Elphaba's castle after the confrontation with Dorothy, signified by the puddle of water and a witch hat on the floor.

A flying monkey, one of Elphaba's servants, crashes through the window. The camera briefly shows Dorothy and her crew — the cowardly lion, the Tin Man, and the scarecrow — on the yellow brick road as the monkey flies over Oz.

Glinda (Ariana Grande) later confirms to the people of Munchkinland, a region in Oz, that Elphaba (Cynthia Erivo) is dead, leading to cheers and joyful singing.

When the crowd asks how Elphaba became evil, Glinda starts telling the story of the witch's life from childhood revealing she and the wicked witch were once friends.

The movie follows the musical and book's plot where Elphaba, the Wicked Witch of the West, didn't start out wicked. She was ostracized in Oz for her green skin tone from an early age.

The rest of the film shows Elphaba's origin story, ending where the end of act one would normally be in the Broadway show.

"Wicked Part Two," which premieres in November 2025, covers act two of the Broadway show. The second act shows the days leading up to Dorothy's arrival and the story of "The Wizard of Oz" from the point of view of Glinda and Elphaba.