Book 1
On the burning lake
Milton opens with the invocation: "Of Man's First Disobedience, and the Fruit / Of that Forbidden Tree" — and the announcement that he will "justify the ways of God to men." The action begins not in Eden but in Hell. Satan and the rebel angels lie burning on a lake of fire after their nine-day fall. Satan wakes; rouses Beelzebub; rouses the rest. He calls them off the lake — "Awake, arise, or be for ever fallen!" — and they form ranks on the shore. The lost legions are named one by one as the false gods they will become in the Old Testament. They build a capital, Pandemonium, in a single hour. The book ends with the council assembled.
Book 2
The council in Pandemonium
The council convenes in the great hall of Pandemonium. Moloch argues for renewed war — better total destruction than this exile. Belial answers smoothly that things could be worse, and counsels patience. Mammon proposes settling for Hell and building it into a kingdom. Beelzebub rises last and proposes what Satan has already decided in private: corrupt the new creation. The plan is adopted. Who will undertake the journey through chaos to Earth? Silence. Satan volunteers alone. He flies to the gates of Hell and finds them guarded by Sin (his daughter, sprung from his head) and Death (their son). They open the gates for him. The book ends with Satan crossing chaos.
Book 3
The bargain in Heaven
The book opens with the famous invocation on Milton's blindness — "Thus with the Year / Seasons return, but not to me returns / Day, or the sweet approach of Ev'n or Morn." The Father, looking down, sees Satan in flight and foresees what will happen. He explains to the Son that Man will fall, freely, and that justice will require death. He asks who, in heaven, will pay. Silence; no creature steps forward. The Son volunteers. The Father accepts and decrees the redemption. Meanwhile Satan, disguised as a junior angel, deceives Uriel — the angel of the sun — and asks the way to Earth. Uriel points it out.
Book 4
Satan in Eden
Satan lands on Mount Niphates and stops. The sight of Eden produces the most exposed soliloquy in the poem: "Me miserable! which way shall I fly / Infinite wrath and infinite despair? / Which way I fly is Hell; myself am Hell." He admits he was given everything by God and chose to lose it. He could repent and will not. He hardens and goes on. He leaps the wall and sees Adam and Eve for the first time, walking together, talking. That night, in the form of a toad, he whispers a dream into Eve's ear. The angelic guard catches him; God hangs golden scales in heaven, weighs the outcomes, and Satan flees.
Book 5
Raphael at table
Eve wakes troubled by her dream. Adam comforts her; they pray together at sunrise. God decides Adam must be warned, so that he cannot later claim ignorance, and sends Raphael down. Adam sees the angel approach in the noon heat and runs to meet him. Eve prepares a feast from the garden; the three of them eat together, Raphael with "real hunger." After the meal Adam asks for the story of the war in heaven. Raphael begins. God elevated the Son; Satan, in envy, gathered his followers in the north of heaven and proposed revolt; Abdiel alone, among Satan's own officers, spoke against him and walked out. The book ends with Abdiel making it back to the loyal side.
Book 6
The war in heaven
Raphael continues. Michael and Gabriel lead the loyal angels against Satan's forces in the open field of heaven. Two days of battle, the rebels gaining the worse of it. On day two Satan invents gunpowder and briefly turns the tide; the loyal host responds by tearing up mountains and hurling them, burying his artillery under stone. On day three God sends out the Son alone, in his chariot, with the brightness of full divinity at last unveiled. The rebels cannot stand. He drives them to the edge of heaven and they fling themselves over the wall, falling nine days through chaos before they hit Hell. Raphael closes with the warning: stand firm.
Book 7
The six days
Adam, having heard the war story, asks for the matching one: how was this world made, and why? Raphael begins again. The Son, after the rebellion, was sent into chaos to draw the boundaries of a new world — to compensate the loss of the rebel third with a new race who, if they prove obedient, will eventually rise to fill the vacant heavenly thrones. Raphael narrates the six days of Genesis: light, firmament, dry land and seas, plants, sun and moon and stars, fish and birds, animals, and last of all Man. He closes by telling Adam why he is here: to be tested, and, if he passes, to ascend.
Book 8
Adam asks for Eve
Adam asks an astronomy question — why is the Earth so small and the heavens so vast? Raphael sketches both the geocentric and heliocentric possibilities and gently warns him off too much speculation: "be lowly wise; / Think only what concerns thee, and thy being." Adam takes the warning and offers his own story in return. Waking on the grass; learning his body; meeting God; being shown the garden and the tree; naming the animals; realizing he was alone; asking God for a partner; God testing the request and granting it; the long sleep; waking to find Eve. Raphael cautions him gently against making Eve the foundation of his whole being, and takes his leave.
Book 9
The Fall
Milton opens with a third invocation: he must "change those notes to tragic." Morning in Eden. Eve proposes they garden separately for the day. Adam objects, citing the warning about the enemy. Eve takes it as a slight on her steadfastness; they argue, and Adam reluctantly gives way. Satan, in the form of the serpent, finds her at the tree, flatters her, claims to have eaten the fruit himself and gained speech, persuades her to eat. She does. Returning to Adam, she tells him; he drops the garland he was making for her, and chooses her over God. They make love feverishly, sleep, and wake angry — the first quarrel after the Fall.
Book 10
Judgment in Eden
The Son descends to Eden and pronounces the curses — the serpent will crawl, woman will bear in pain, man will eat by the sweat of his brow. Before he leaves, he clothes Adam and Eve with skins, "as a Father." Meanwhile Sin and Death build a great causeway across chaos from Hell to Earth — the road by which death enters the world. Satan, returning to Pandemonium expecting acclaim, is transformed into a serpent on his throne, his army hissing below him. On Earth, after a long bitter night of recrimination, Eve breaks first and offers to take the punishment alone. Adam refuses; the two of them kneel together at the place where the Son judged them.
Book 11
The vision of history
God accepts the repentance, but the sentence stands: they cannot remain in Eden, because the tree of life is now too dangerous for fallen creatures. He sends Michael down to lead them out. Eve weeps for the garden; Adam grieves for the place where God walked with him. Before they leave, Michael takes Adam up onto the highest hill of paradise and shows him the future. Cain killing Abel — the first death Adam sees. The cities of Cain's descendants. The flood. Noah and his family alone surviving in the ark. The covenant, and the rainbow. Adam weeps, questions, watches. The book ends with the rainbow over the receded waters and Michael preparing to continue.
Book 12
Hand in hand
Michael resumes. Abraham, the Israelites in Egypt, the law on Sinai, the prophets, the exile, the return; and finally a child born in Bethlehem — the seed promised to the woman. Adam asks how the seed can bruise the serpent's head if he himself dies. Michael explains: the death is the bruising; the resurrection seals it. Adam is consoled: "O goodness infinite, goodness immense! / That all this good of evil shall produce, / And evil turn to good." Michael adds the last lesson: Adam may possess "a paradise within thee, happier far." The poem closes: "they hand in hand with wandering steps and slow, / Through Eden took their solitary way."