The duo are left in possession of a sacred medallion which supposedly records the location of a hidden treasure.

Two Americans, Abbott and Costello, who are stranded in Cairo, Egypt, overhear Dr. Gustav Zoomer discussing the mummy Klaris, the guardian of the Tomb of Princess Ara.

The followers of Klaris, led by Semu, overhear the conversation along with Madame Rontru, a businesswoman interested in stealing the treasure of Princess Ara.

Abbott and Costello go to the doctor's house to apply for the position to accompany the mummy back to America.

However, two of Semu's men, Iben and Hetsut, murder the doctor and steal the mummy just before Abbott and Costello arrive.

Rontru tells them to meet her at the Cairo Café, where Abbott and Costello learn from a waiter that the medallion is cursed.

[2] Although Abbott and Costello were called "Pete Patterson" and "Freddie Franklin" in the script and in the closing credits, they used their real names onscreen during filming.