Dionysus, Greek god of wine, fertility, ritual madness, and ecstasy returns to his hometown of Thebes, having sent the women of Asia wild with his religion. He explains that hes here to avenge his mother, Semele, who he feels was wronged by her sisters and is being disrespected by the current king of Thebes, Dionysuscousin Pentheus. Dionysus tells his backstory: Semeles lover was Zeus, king of the gods, and their relationship made Zeuswife, Hera, jealous. She tricked Semele into asking Zeus to reveal himself in his true form, a dangerous lightning storm that fatally struck Semele. Zeus then stitched Dionysus, his unborn son, into his thigh for protection. Dionysus is angry that Semeles sisters and Pentheus cast doubt on this story, suggesting it was invented by Cadmus, the sistersfather and Dionysus and Pentheusgrandfather, in order to save face over Semeles embarrassing affair with a mortal. Accordingly, Dionysus wants to exact revenge and prove his godliness in doing so.