In Heaven, Lucifer, unable to abide the supremacy of God, leads a revolt against divine authority. Defeated, he and his followers are cast into Hell, where they lie nine days on a burning lake. Lucifer, now called Satan, arises from the flaming pitch and vows that all is not lost, that he will have revenge for his downfall. Arousing his legions, he reviews them under the canopy of Hell and decides his purposes can be achieved by guile rather than by force.
Under the direction of Mulciber, the forces of evil build an elaborate palace, Pandemonium, in which Satan convenes a congress to decide on immediate action. At the meeting, Satan reasserts the unity of those fallen and opens the floor to debate regarding what measures should be taken. Moloch advises war. Belial recommends a slothful existence in Hell. Mammon proposes peacefully improving Hell so that it might rival Heaven in splendor. His motion is received with great favor until Beelzebub, second in command, rises and informs the conclave that God has created Earth, which he has peopled with good creatures called humans. It is Beelzebub’s proposal to investigate this new creation, seize it, and seduce its inhabitants to the cause of the fallen angels.
Announcing that he will journey to Earth to learn for himself how matters are there, Satan flies to the gate of Hell. There he encounters his daughter, Sin, and his son, Death. They open the gate, and Satan wings his way toward Earth.
God, in his omniscience, has beheld the meeting in Hell, knows the intent of the evil angels, and sees Satan approaching Earth. Disguised as various beasts, Satan acquaints himself with Adam and Eve and with the Tree of Knowledge, the fruit of which God has forbidden to them.
Uriel, learning that an evil angel has broken through to Eden, warns Gabriel, who appoints two angels to hover about the bower of Adam and Eve. The guardian angels arrive too late, however, to prevent Satan, in the form of a toad, from beginning his evil work. He has influenced Eve’s dreams.
Upon awaking, Eve tells Adam that in her strange dream she was tempted to taste of the fruit of the Tree of Knowledge. God, seeing that danger to Adam and Eve is imminent, sends the angel Raphael to the garden to warn them. At Adam’s insistence, Raphael relates in detail the story of the great war between the good and the bad angels that led to the fall of the bad angels to eternal misery in Hell. At Adam’s further inquiries, Raphael tells of the creation of the world: how Earth was created in six days, an angelic choir singing the praises of God on the seventh day. He cautions Adam not to be too curious, saying that there are many things done by God that are not for humans to understand or to attempt to understand. Adam then tells how he has been warned against the Tree of Knowledge of Good and Evil, how he asked God for fellowship in his loneliness, and how Eve was created from his rib.
After the departure of Raphael, Satan returns to the garden as a mist and enters the body of a sleeping serpent. In the morning, as Adam and Eve proceed to their day’s occupation, Eve proposes that they work apart. Adam, remembering the warning of Raphael, opposes her wishes, but Eve prevails, and the two part. Alone, Eve is accosted by the serpent, which flatters her into tasting the fruit of the Tree of Knowledge. Eve, liking what she has tasted, takes the fruit to Adam, who is horrified when he sees what Eve has done. In his love for Eve, however, he also eats the fruit.
Having eaten, Adam and Eve know lust for the first time, and after their dalliance they know sickening shame. They also eat many apples, adding gluttony to their list, which they are rapidly completing, of the seven deadly sins. The guardian angels now desert the transgressors and return to God, who approves their efforts, saying they could not have prevented Satan from succeeding in his mission.
Christ descends to Earth to pass judgment. Before Adam and Eve, who had been reluctant, in their shame, to come out of their bower to face him, Christ sentences the serpent to be forever a hated enemy of humankind. He tells Eve that her sorrow will be multiplied by the bearing of children and that she will be the servant of Adam to the end of time. Adam, says Christ, will eat in sorrow; his ground will be cursed, and he will eat bread only by toiling and sweating.
Meanwhile, Death and Sin, having divined Satan’s success, leave the gates of Hell to join their father on Earth. Within sight of Earth they meet Satan, who delegates Sin and Death as his ambassadors on Earth. Back in Hell, Satan proudly reports his accomplishments to his followers. He is acclaimed, however, by hisses as his cohorts become serpents, and Satan himself is transformed into a serpent before their reptilian eyes. Trees similar to the Tree of Knowledge appear in Hell, but when the evil angels taste the fruit, they find their mouths full of ashes.
God, angered at the disaffection of Adam and Eve, brings about great changes on Earth. He creates the seasons to replace eternal spring and creates the violence and misery of storms, winds, hail, ice, floods, and earthquakes. He causes all of Earth’s creatures to prey upon one another. Adam and Eve argue bitterly (adding anger to their sins) until they realize they have to face their common plight together. Repenting their sins, they pray to God for relief. Although Christ intercedes for them, God sentences them to expulsion from Eden and sends the angel Michael to Earth to carry out the sentence. Adam and Eve, lamenting their misfortune, contemplate suicide, but Michael gives them new hope when he brings to Adam a vision of life and death; of the rise and fall of kingdoms and empires; of the activities of Adam and Eve’s progeny through their evil days to the flood, when God will destroy all life except that preserved by Noah in the ark; and of the subsequent return to evil days and Christ’s incarnation, death, resurrection, and ascension as the redeemer. Despite the violence, evil, and bloodshed in the vision, Adam and Eve are pacified when they see that their children will be saved. They walk hand in hand from the heights of Paradise to the barren plains below.