In Cairo, archaeologist Steve Banning (Dick Foran) unearths a vase that he believes could lead him to the ancient tomb of Princess Ananka. Unknown to Steve, his colleague, Professor Andoheb (George Zucco), is also the High Priest of Karnac who holds the secrets of Karas, a mummy who guards Ananka's tomb. Upon receiving funds from magician Solvani (Cecil Kellaway) and his daughter, Marta (Peggy Moran), Steve and the Solvanis embark on an expedition to the grave site, where Karas awaits.