The Mad Mummy, a denizen of the Nether World, wreaked havoc on ancient Egypt by indiscriminately slaying men and women, cackling over his human carnage, and by attempting to overthrow the world of the living. The ancient Shazam imprisoned the Mummy in a pyramid tomb for the Mummy’s crimes. Shazam dropped the tomb to the bottom of the ocean.

Thousands of years later… archeologists Professor Joplin and Professor Beatty discovered the Pyramid of Peril after they deciphered ancient parchments leading to its location. When a giant octopus attacked Beatty during a dive to discover the entrance of the tomb, the Mighty Marvels flew in to rescue the terrified diver. Cap, Mary, and Junior also raised the pyramid and delivered it to dry land. In exchange for opening the pyramid, the Marvels struck a deal with Joplin so that their alter egos could join in on the discovery.

Inside the pyramid, Joplin and his team ignored repeated warnings not to let loose the Mad Mummy even a warning written by the ancient wizard Shazam! Joplin cavalierly opened the mummy’s sarcophagus and the loosed the still animated mummy on the modern world. The mummy quickly overcame both Joplin and his party and the Marvels in their human guises of Billy, Mary, and Freddy trapping them all in a giant stone Sphinx. The mummy launched the Sphinx and his captives towards Fawcett City in an attempt to kill thousands. Billy was able to remove his gag in time to change to Captain Marvel and save the city. Cap quickly freed Freddy and Mary and the reunited Marvel Family took off to battle the Mad Mummy!

The mummy used an ancient device named the Horn of Horror to release a plague of demons to slow the Marvels down but the Marvels quickly overcame the demons.

After destroying the mummy’s pyramid, Billy, Mary, and Freddy paid a quick visit to Shazam, who told them of the grisly history of the mummy and charged them with stopping the mummy.

In the meantime, the Mad Mummy has used his Horn of Horror to bring forth a horde of other mummies that captured the three kids. The muumy used his Sphinx Ray to silence the kids so that they couldn’t say their magic words. He then tortured and forced the kids to build a new Pyramid of Peril.

To escape the clutches of the mummy, Billy suggested that they play dead. Believing that the children had passed away, the Mad Mummy wrapped the children in mummy cloth and deposited them in open sarcophaguses in the new Pyramid of Peril. The kids then snuck out of the tomb and up on the mummy grabbing and destroying the mummy’s Sphinx Ray. Now able to speak, the kids changed to their Marvel forms and quickly defeated the mummy horde.

The Marvel’s caused an earthquake, which swallowed up the mummy’s Horn of Horror. After quickly capturing the mummy, the Marvel’s delivered him to Shazam who sealed the mummy back in his sarcophagus. The Marvel’s dropped the new Pyramid of Peril in the deepest part of the ocean and the Mad Mummy has not been heard from since.