On the beach one night, Christine Faber, two years a widow, thinks she hears her late husband Paul calling out of the surf...then meets a tall dark man, Alexis, who seems to know all about such things. After more ghostly manifestations, Christine and younger sister Janet become enmeshed in the eerie artifices of Alexis; but he in turn finds himself manipulated into deeper deviltry than he had in mind...
Ali Baba, son of the Kalif of Bagdad is brought up by the 40 Thieves after his father is killed by the soldiers of Hugalu Khan, who received the necessary information by traitor Cassim. Ali becomes the leader of the thieves and they are fighting for the freedom of his land. Per chance Ali captures the fiancée of Hugalu Khan, who turns out to be his girl friend Amara. After a few misunderstandings Ali uses her wedding day with Hugalu Khan as the day for the liberation of Bagdad.
Curious about the effects of an ancient Mayan nerve gas on humans, a scientist exposes his young assistant and turns him into a mindless ghoul that must have human heart substance to live.
A high priest travels to America with the living mummy Kharis (Lon Chaney Jr.) to kill all those who had desecrated the tomb of the Egyptian princess Ananka thirty years earlier.
Several subplots revolve around story of mutant embryo in jar that exercises control over the lives of those who come into contact with it.