The Land of Oz is ruled by Prime Minister Kruel (Josef Swickard), aided by Ambassador Wikked (Otto Lederer), Lady Vishuss (Virginia Pearson), and the Wizard (Charles Murray), a ”medicine-show hokum hustler”. When the discontented people, led by Prince Kynd (Bryant Washburn), demand the return of the princess, who disappeared while a baby many years before, so she can be crowned their rightful ruler, Kruel has the Wizard distract them with a parlor trick: making a female impersonator (Frederick Ko Vert) appear out of a seemingly empty basket. Kruel sends Wikked on a mission.
Meanwhile, in Kansas, Dorothy (Dorothy Dwan) lives on a farm with her relatives. While Aunt Em (Mary Carr) is a kind and caring woman, Uncle Henry (Frank Alexander) is an obese man with a short temper who shows little love for his niece. He also abuses his farmhands: Snowball (credited to G. Howe Black, a stage name for Spencer Bell, who frequently appeared in Semon’s films) and Hardy’s and Semon’s unnamed characters. The latter two are both in love with Dorothy, who favors Hardy’s character. Aunt Em reveals to Dorothy that she was placed on their doorstep as a baby, along with an envelope and instructions that it be opened only when she turned 18.
On her 18th birthday, however, Wikked and his minions arrive at the farm by biplane and demand the envelope. When Uncle Henry refuses to hand it over, Wikked suborns Hardy’s character by promising him wealth and Dorothy. Wikked then has Dorothy tied to a rope and raised high up a tower; his men start a fire underneath the rope. Hardy’s character finds the note, but Semon’s character takes it and saves Dorothy, only to have Wikked and his men capture them all at gunpoint.
Then a tornado suddenly strikes. Dorothy, the two rivals for her affections and Uncle Henry take shelter in a shed. It (and Snowball) are carried aloft and land in Oz. Dorothy finally reads the contents of the envelope; it declares that she, Princess Dorothea, is the rightful ruler of Oz. Thwarted, Kruel blames the farmhands for kidnapping her and orders the Wizard to transform them into something else, such as monkeys, which he is of course unable to do. Chased by Kruel’s soldiers, Semon’s character disguises himself as a scarecrow, while Hardy’s improvises a costume from the pile of tin in which he is hiding. They are still eventually taken captive. During their trial, the Tin Man accuses his fellow farmhands of kidnapping Dorothy. Kynd has the Scarecrow and Snowball put in the dungeon.
Kruel makes the Tin Man ”Knight of the Garter” and Uncle Henry the ”Prince of Whales”. Wikked suggests he retain his power by marrying Dorothy. The Wizard helps the two prisoners escape by giving Snowball a lion costume, which he uses to scare away the guards. Though the Scarecrow manages to reach Dorothy to warn her against Kruel, he is chased back down into the dungeon by the Tin Man, and ends up getting trapped inside a lion cage (with real lions) for a while. He and Snowball finally escape.
When Kynd finds Kruel trying to force Dorothy to marry him, they engage in a sword fight. When Kruel’s henchmen intervene and help disarm Kynd, the Scarecrow saves Dorothy and Kynd. Defeated, Kruel claims that he took Dorothy to Kansas in order to protect her from court factions out to harm her, but she orders that he be taken away.
The Scarecrow is heartbroken to discover that Dorothy has fallen for Prince Kynd. He then flees up a tower from the Tin Man, who tries to blast him with a cannon. Snowball flies a biplane overhead, and the Scarecrow manages to grab a rope ladder dangling underneath it. However, the ladder breaks, and he falls. The scene shifts abruptly back to the little girl, who had fallen asleep. She wakes up and leaves. The grandfather reads from the book that Dorothy marries Prince Kynd and they live happily ever after.