Although Mercury admits to pitying Prometheus, he is bound to oppose Prometheus who stands against Jupiter. He asks Prometheus to reveal the secret of Jupiter's fate only Prometheus knows, and Prometheus refuses to submit to Jupiter's will. Mercury tries to barter with Prometheus, offering him the pleasure of being free from bondage and being welcomed among the gods, but Prometheus refuses. At the refusal, Jupiter makes his anger known by causing thunder to ring out across the mountains. Mercury departs at the omen, and the furies begin to taunt Prometheus by saying that they attack people from within before they attack Prometheus without. After all of the furies but one leave, Panthea and Ione despair over Prometheus's tortured body. Prometheus describes his torture as part of his martyrdom and tells the remaining fury, "Thy words are like a cloud of winged snakes; / And yet I pity those they torture not," to which the fury departs.