The story opens in a Hindu temple of Buddha in Northern India, where six priests are performing the rites of their ancient religion. A band of Tartar coolies steal in and attack the devotees. The sacred eye of Buddha, a magnificent emerald, flashes fire, and the coolies fall back in awe. One overcomes his fear and gouging the stone from the head of the idol escapes. One of the priests, just as he is dying, curses the despoilers and pronounces a malediction upon the possessors of the stone. Djalma, the high priest, discovers the dead bodies and vows to devote his life to the recovery of the sacred stone. The curse soon shows its effects. The coolies, who have reached the desert, quarrel, and one kills the others. In the jungle he becomes a madman, and throws the emerald away. It hangs suspended in the air, and as he dies it settles on his breast. It is found by a caravan who take it to Sir Hugh Wheeler, the English commandant, who purchases it for his niece. The merchant who sells it dies suddenly. The evil power still follows the stone. On the parade ground at the English headquarters, a priest harangues the Sepoy troopers, telling them that they are being defiled by using greased bullets. They throw down their arms and begin the Sepoy rebellion. Nana Sahib offers safe conduct to all English troops and residents, then villainously slaughters the soldiers, including Sir Hugh, while the women and children are taken back inside the gates. Djalma, the high priest, sees the fate of Sir Hugh, and smiles as he observes the fatal toll of the stone. All of the white people are slaughtered, except a little baby, which a native woman secretes, and gives to the high priest for adoption. Djalma names him Afga and swears that he will eventually restore the stone to its sacred resting place. Twenty-five years elapse, and each owner of the emerald has some calamity befall him. Colonel and Mrs. Van Alston give their daughter, Nellie, the emerald. This is observed in a vision by the high priest, Afga, shortly after he has promised the dying Djalma that he will work unceasingly to restore the stone. Afga's astral body journeys to London, while Nellie sleeps and worships the gem. Nellie, in a dream, sees him and the idol, and connects the absence of the idol's eye with her emerald. She awakes, to find the stone suspended in midair, and faints from fright. Nellie's illness puzzles the doctors. Colonel Van Alston is ordered to India, and takes his wife and daughter with him. In viewing the sights at Cawnpore they come to the Temple of Buddha. Afga and Nellie meet, and Afga, gaining the Colonel's consent to cure Nellie, lays his hands on her brow and she becomes well. Meanwhile native devotees of the Goddess Thug, observing the valuable stone on Nellie's neck, attempt to strangle her. Afga observes this in a vision, and saves the girl by turning the leader into a dog. The following day Nellie goes to the temple, and meets Afga. He takes her before the idol and tells her the story of the emerald. She returns it and he replaces it in the head of the Buddha, where it flames with fire. Then Afga folds Nellie in his arms.