Diamond Ring follows the story of conflict between the spirit of Mrs. Gladys and members of Chidi's cult group, XG. In a bid to display his fitness for a life in the secret cult, Chidi, a freshman in the university and the only child of his parents; Chief and Mrs. Ijeoma Dike steals a diamond ring from Mrs. Gladys' corpse. The spirit of Mrs. Gladys in turn haunts Chidi and his friends. The members of the cult begin to die successively. Chidi is struck by a peculiar sickness which could not be treated by orthodox medicine. The journey to find his healing culminates in the return of the diamond ring to Mrs. Gladys' corpse.