A group of Cajuns are worried about the government clearing of a local swamp, as they believe the marsh lands are haunted by the mummy Kharis, who carried the reincarnation of his ancient love, Princess Ananka, into its depths twenty-five years earlier. Pat Walsh, the superintendent in charge of the swamp clearing, is met by two representatives of the Scripps Museum, archaeologists Dr. James Halsey and Dr. Ilzor Zandaab, who ask for his help in excavating the remains of Kharis and Ananka. Soon thereafter, the murdered body of one of Pat's workmen is discovered in the swamps, and Halsey finds what seems to be Kharis' empty grave nearby. Unknown to Halsey, Zandaab, a high priest in the ancient religion of Amon-Ra, has unearthed Kharis with the help of Ragheb, a local workman, and now plans to re-animate the mummy with tanna leaves so that Kharis can recover Ananka's body and they both can be returned to their ancient tombs in Egypt. After Kharis is re-animated by Zandaab inside an abandoned monastery, the mummy kills Michael, the self-appointed caretaker of the chapel. Later, in the midst of the swamp's excavation, an old and withered Ananka emerges from the marshes, but is transformed into a beautiful, youthful woman upon the touch of the sun's rays. She is then discovered by Cajun Joe, a foreman, and he takes the amnesiac woman to Tante Berthe's café. Ragheb, however, hears Ananka calling Kharis' name and rushes to inform Zandaab. Kharis is then sent to the café to reclaim his love, but Ananka does not recognize him and runs away. She faints near the roadway, where she is found by Halsey and Betty Walsh, Pat's secretary and niece. Meanwhile, Tante is discovered strangled to death, with ancient mold around her neck. Later, Ananka becomes Halsey's assistant, and the archaeologist is amazed by her unexplained expertise in ancient Egypt. Upon seeing Zandaab, however, Ananka goes into a trance and begins calling for Kharis, but the trance is quickly broken when she is shaken by Halsey. That night, Kharis once again tries to reclaim Ananka, but when she makes her escape, the mummy kills Dr. Cooper, the local physician. Seeing Ananka as the common link in the string of murders, Halsey and the workmen search the swamps for the missing woman. During the search, Cajun Joe is strangled by Kharis. Afterward, Ananka returns to the worker's camp, where she seeks refuge in Betty's tent. This time, Kharis manages to capture his love and goes back to the deserted monastery, where Zandaab feeds Ananka the sacred tanna leaves. Betty and the lustful Ragheb then arrive, but when Zandaab insists on killing the innocent Betty to preserve the secret of Kharis and Ananka, Ragheb stabs the high priest to death. Halsey then arrives at the monastery, where he and Ragheb fight over Betty. As Ragheb is about to kill Halsey, Kharis enters and, enraged by the death of Zandaab, tears down a wing of the monastery in an attempt to get at the murderous Ragheb. Both Kharis and Ragheb are buried in the rubble, and Ananka's mummified body is later found by Halsey and Pat. Halsey then makes plans to unearth Kharis and return both mummies to the Scripps Museum, and publicly announces his romantic intentions toward Betty.