Core Narrative Summary
Book 9 opens with Satan returning to Eden, disguised as a serpent, after observing the vulnerable bond between Adam and Eve. He targets Eve alone, exploiting her curiosity and desire for self-reliance to persuade her to eat from the forbidden tree. When Adam discovers what Eve has done, he chooses to join her in transgression rather than face eternal separation. Their actions break their covenant with God, and they are immediately cast out of Eden, facing physical and spiritual suffering for the first time.