An onscreen text warns of the superstitious belief in a
vorvolaka, a malevolent force in human form. The film properly begins during the
Balkan Wars of 1912. While his troops are burying their dead, General Pherides and American reporter Oliver Davis visit the Isle of the Dead to pay their respects to the General's long-dead wife. They discover the crypt despoiled; hearing a woman singing on the supposedly uninhabited island, they set out to find her. They also find retired Swiss archeologist Dr. Aubrecht, his Greek housekeeper Madame Kyra, British diplomat Mr. St. Aubyn and his pale and sickly wife, her youthful Greek companion Thea, and English tinsmith Andrew Robbins. Aubrecht apologizes for his part 15 years before in inspiring local peasants to
rob graves for valuable Greek artifacts. Kyra whispers to Pherides that a
vorvolaka, in the guise of the red and rosy Thea, is in their midst. Pherides laughs at such superstition and accepts Aubrecht's invitation to spend the night as his guest. The next morning, Robbins is dead. Dr. Drossos is summoned; he determines the cause to be
septicemic plague and quarantines the island. He explains how plague is passed and how it may be eradicated in one day if the hot, dry
sirocco winds arrive. The archaeologist says that Kyra's explanation – that God sends the plague to punish them for harboring a
vorvolaka – makes just as much sense. When Mr. St. Aubyn dies, the General demands that his body be buried immediately, to the horror of the
cataleptic Mrs. St. Aubyn, who fears
premature burial. Next to die is Dr. Drossos, proving that the advice of modern science does not guarantee victory over the disease. Suspicion returns to Thea, and Kyra harasses her with taunts and threats. Pherides vows that he will kill Thea if evidence appears that she is
vorvolaka. Fearing for Thea's life, Oliver plans to escape with her, but Pherides destroys the only boat. Mrs. St. Aubyn falls into a cataleptic trance; everyone except Thea believes her to be dead, and they entomb her. Oliver and Aubrecht believe the cause to be plague, but Kyra and Pherides believe it to be the doing of the
vorvolaka. Oliver advises Thea to stay away from Pherides. The winds change, and the sirocco has arrived, but it is too late for Pherides, who exhibits symptoms of the plague. Mrs. St. Aubyn awakens from her catalepsy but has been driven insane by being buried alive. Escaping the tomb, she kills Kyra, stabs Pherides as he attempts to kill Thea, and then leaps off a cliff to her death. As Pherides is dying, he swears that he has seen the
vorvolaka and warns that she must be killed. "It is done", says Dr. Aubrecht, sympathetic to Pherides' peculiar madness. "The general was simply a man who was trying to protect us", he offers as
eulogy. ==Cast==