Denton, an anthropologist of note, meets by accident a new neighbor, an attractive girl, whose father insists upon her marriage to a man whom he favors because of his wealth. Denton and the girl are mutually attracted and to Denton comes a vague but haunting belief that they have met before. Worn out by overstudy, he becomes seriously ill with rain fever and the mind pictures he has of his fair neighbor fade into a vision of a prehistoric existence, where he wanders as a stone age savage, meets ...