The movement from pure ritual to drama in Greece involves substituting stories of heroes for the story of Dionysos, so that the plot taken from the long story of Medea or Agamemnon, for example, becomes a metaphor for the process of intoxication and purgation associated originally with Dionysos. It is in the works of Aeschylus, Sophocles, and Euripides, and to a lesser extent Aristophanes, that we can trace this metaphorical transference and the use of mythology in general in the Greek drama that took place in the City Dionysia.