The story is based on the mythology surrounding Bacchus and Ariadne (Ariane). The Gods, among them demi-god Bacchus, appear in human form in ancient India to attempt to persuade the people away from the pervading Buddhist influence. Ariane has followed them, convinced that Bacchus is in fact Theseus, her unrequited love. In the end, Ariane sacrifices herself to save humanity and in doing so, Bacchus becomes a God.
Although not a proper sequel, as Ariane dies in both pieces, Bacchus is a companion to Massenet's earlier opera, Ariane. Of Massenet's twenty-five operas, Bacchus is probably the least known, without a modern performance history or single modern recording of even an excerpt.