Little Dorothy Gale of Kansas, like so many girls her age, dreams frequently of what lies over the rainbow (Over The Rainbow). One day a twister hits her farm and carries her away. At the end of the rainbow, she finds herself in picturesque Munchkinland; home of the fascinating people, the Munchkins. In this famous land of Oz, Dorothy meets her first fairyland figure: the Sorceress of the North.
The Munchkins fête Dorothy as a heroine, because in landing, her house has accidentally killed the Wicked Witch of the East, who had long tormented the Munchkins (Munchkinland/Ding Dong The Witch Is Dead). Dorothy wants to return to Kansas, fearing her Aunt Em and Uncle Henry will worry about her. The Sorceress advises Dorothy that only the great Wizard of Oz can help her get back to Kansas. But Dorothy has an enemy, the Wicked Witch of the West, sister of the dead Wicked Witch of the East, who vows revenge. The witch is frightened away on her first encounter with Dorothy by a protective mark, which the Sorceress placed on Dorothy's forehead. Dorothy must find the Munchkins, again, to get directions to the Emerald City. She gets directions to Munchkinland from the Scarecrow who joins her (If I Only Had A Brain). The Wicked Witch of the West puts a curse on the bridge, which leads them to the Munchkins. Finally able to outsmart the witch, they make it to the side of the bridge where Munchkinland is located, and meet the Tin Woodman (If I Only Had A Heart). The three travelers find the Munchkins and get directions to the Emerald City (We're Off To See The Wizard).
The Munchkins bring the three friends to the forest where the yellow brick road begins. They warn the travelers of lions, tigers, bears and Jitterbugs (fantastic dancing creatures, half animal, half plant, under the Wicked Witch of the West's power). The travelers meet a lion, who ends up joining them on their journey (If I Only Had The Nerve). The Wicked Witch of the West attempts to stop the journey by setting her Jitterbugs on the three friends (Jitterbug). Luckily, Dorothy is able to contact the Sorceress of the North, who freezes the Jitterbugs, and saves them from being danced to death.
Finally at the Emerald city, we are treated to the Royal Army of Oz Changing Of The Guard. Dorothy introduces herself and her friends to Lord Growlie, his daughter Gloria and the Army. Lord Growlie explains that the Wizard of Oz is the most powerful Wizard in the world, but that if you bother him with a foolish request, he could destroy you as quickly as a snap of his fingers. While Lord Growlie notifies the Wizard of Oz he has visitors, Gloria entertains Dorothy (The Merry Old Land Of Oz), and the three other travellers tour the palace. Dorothy sings (Evening Star) about love and romance.
When Dorothy and her friends finally meet the Wizard, he is forceful and looks like a beast. He demands that they kill the Wicked Witch of the West before he will grant them their wishes. Without knowing that the Witch has a recipe, which will break the Sorceress' protective mark on Dorothy's forehead, the four travelers go to the Witch's castle. Along the way, the Witch eavesdrops on their conversation and learns of their plans to kill her. The Witch casts a spell on Dorothy, which takes the girl away from her friends and brings her to the castle. The three remaining travelers hurry to rescue Dorothy. The Witch plans to kill the four friends by shrinking them into nothing, in a cauldron of magic water. The Scarecrow, Tinman and Lion disguise themselves as ghosts to rescue Dorothy. Their true identities are accidently revealed, and the Witch threatens the Scarecrow with fire. Dorothy protects the Scarecrow by pulling the Witch back into the full cauldron, to extinguish the fire. The magic water puts out the fire and shrinks the Witch into nothing (Ding Dong The Witch Is Dead (reprise).
Back at the Emerald City the Wizard Of Oz throws a party in honor of the four friends. When they finally meet the Great Oz, the four discover he is an ordinary man, not a great beast or a powerful wizard. Nevertheless, the Wizard of Oz is able to grant everyone's wishes. He gives the Lion a medal to represent courage, the Tinman a watch to show his large heartedness, and the Scarecrow a diploma to signify graduation from advanced study. The Great Wizard of Oz escorts Dorothy back to Kansas in his rocket ship.