In ancient Egypt, an evil sorcerer, Scarab, kills the pharaoh's son, Prince Rapses, so he can use the boy's soul to become immortal. Entombed alive for his crime (Rapses' body was also never found), Scarab revives in the modern world and begins his search for Rapses' reincarnation, a San Francisco-dwelling boy named Presley Carnavon. Rapses' bodyguards, Ja-Kal, Rath, Armon, and Nefer-Tina, rise from the dead to protect him from Scarab. Each of the mummies is aligned with the power of an Egyptian god and are able to call upon it for magical armor and powers to fight superhuman evildoers, although once their strength is exhausted they must rest in their sarcophagi to regain the ability. The mummies also have the power to make horrifying face, usually employed to scare away nosy bystanders.

In addition to Scarab, the mummies often had to contend with gods and spirits from Egyptian myth summoned to the modern world, including Anubis, Set, Geb, Apep, Bast, Sekhmet and Bes, usually as part of one of Scarab's schemes that went out of his control.