- The narrator interjects, saying he wishes it had been possible for mankind to have been warned of Satan's plans so they could have avoided succumbing to temptation.
- Satan is angry about losing the battle in Heaven, and he plans to take his anger out on mankind. He can never really escape from Hell, because the true Hell is within him.
- He addresses the sun. He tells him he hates his beams because they remind him of what he once was.
- But he was already so close to the top, he couldn't resist trying to go all the way, trying to defeat God. He didn't want to remain in a state of "subjection" to God, he says.
- Satan is really upset. His despair is only getting worse: "Which way I fly is Hell; my self am Hell" (4.75).
- Satan says God will never forgive him because he knows that if he (Satan) were allowed to re-enter Heaven, he would eventually try to overthrow God again. There will never be peace.
- Satan therefore resolves on evil because he has no hope or fear: "Evil be thou my Good," he says. He and God will rule a "Divided Empire."
- Satan is so angry that his face changes colors: "each passion dimmed his face / Thrice changed with pale, ire, envy and despair" (4.114-5). Uriel notices this from his position in the sun.
- Satan approaches the edge of Paradise, which is at the top of a steep, overgrown hill. The sides of the hill are covered with bushes and trees. The wall of Paradise stands tall at the top.
- Above the wall can be seen a "circling row / Of goodliest trees loaden with fairest Fruit." Pleasant air, "gales," and "perfumes" emanate from Paradise.
- Satan can't climb the hill; it's so thick and wooded. The only gate is on the other side (the eastern side); he decides to just jump clear over it, like a wolf or a thief.
- He lands on the top of the Tree of Life to observe Eden; it is "A Heaven on Earth." Right next to the Tree of Life is the Tree of Knowledge, which caused humanity's "death."
- Paradise is as beautiful as one would think; gorgeous lawns, sheep grazing in peace, every succulent type of fruit, every type of flower, ambrosial odors, etc.; even the roses are "without thorn."
- Satan sees all the "delight" of Paradise "undelighted," and then notices "Two of far nobler shape erect and tall."
- One is male, the other female; they seem (to Satan) somewhat unequal. "For contemplation he and valor formed, / For softness she and sweet attractive grace." He looks strong, and she looks soft and sweet.
- They're both naked; the woman has long hair down to her waist; Adam's hair only goes to his shoulders.
- She's clearly subservient to him, but it's not slave-like. She yields with the utmost love.
- They are "the loveliest pair / That ever since in love's embraces met" (4.321-322). They've just finished gardening and are sitting down to a meal of nectarines. All the animals play near them; we do mean all! Milton mentions lions and elephants.
- Satan sees all this and exclaims, "Oh Hell." He says little do they know what's in store for him. Soon, he'll drag them (so he thinks) to Hell.
- He jumps down from the tree among the animals and changes his shape into a lion, then a tiger. His ears perk up as he hears Adam address Eve.
- Adam says God must be infinitely good; he gave them Paradise, has absolutely no need for anything they can provide, and has only given them one easy rule: don't eat from the Tree of Knowledge.
- Eve replies, saying essentially "you're right honey." She remembers when she was born. She explains how she wandered over to a lake and was startled by her own reflection in the water. A voice led her to Adam.
- She tried to turn away from Adam because he was "less faire" and "less amiably mild" than her own reflection in the water.
- Adam called her back, telling her that she was created from his side and that he claims her as his "other half."
- Satan sees all this and is sickened; he calls it a "Sight hateful, sight tormenting." They get to have a paradise and each other and he's stuck in Hell. Ugh!
- He says he can't understand why they're not allowed to possess knowledge. He will "excite" their desire to know, and trick them into disobeying God's one command.
- In the meantime, he plans to find out more information, and goes in search of other angels that might be hanging out in Eden.
- The sun is setting in the west. The light glances off the eastern gate of Paradise, which ascends to the clouds and Heaven. Gabriel, an angel, sits at the top and watches over Paradise.
- Uriel comes to Gabriel on a sunbeam, just like a shooting star. He tells Gabriel that a strange guy came asking for information earlier. He later recognized him as "one of the banished crew."
- Gabriel says if someone snuck into Eden, he'll find out by morning who it is. Uriel departs as night falls. A beautiful description of twilight and evening ensues.
- Adam says to Eve that it's time for bed; God has ordained periods of labor and rest, after all. He tells her about some of their laborious gardening projects for the next day.
- Eve says she obeys whatever Adam says because "so God ordains." She really loves Adam, so much so that she wouldn't like any of it if he weren't there to share it with her.
- Adam responds, telling Eve all about why the stars and heavens shine. He also talks about various "celestial voices" that he has heard about night, singing the praises of God.
- Adam and Eve enter their "bower," a pretty "lodge" with all kinds of flowers on the walls and floor. As they approach, they look up to the sky and praise God and his creations.
- They enter their home, and make love: "nor Eve the Rites/ Mysterious of connubial love refused" (4.743-744). This is Paradise, and God said be fruitful and multiply. Besides, this is the purest love imaginable.
- While they sleep, Gabriel tells his second in command, Uzziel, to take a squadron and check the south of Eden. He (Gabriel) will check the north with another group.
- He orders Ithuriel and Zephon, two other angels, to search for the rebel angel in Eden. They find him disguised as a toad, whispering poisonous thoughts into Eve's ear.
- Ithuriel touches him with his spear, and he then turns back to his normal shape. They ask Satan which rebel angel he is.
- He responds by saying, "Don't you guys know who I am? If you don't, you must be really low on the totem pole because all important angels know me."
- Zephon responds by saying he looks different than when he was in Heaven. He now looks like his new home, Hell. He says Satan must answer to Gabriel.
- After some more banter, they lead Satan to where Gabriel and his squadrons are waiting. Gabriel recognizes Satan as the leader of the fallen angels and tells his soldiers to be ready for a fight.
- Gabriel asks Satan why he's left his prison in Hell. Satan replies that he used to think Gabriel was wise but not after this question. Who wouldn't try to leave the gloom of Hell for something better?
- Gabriel sarcastically responds, saying what a shame that Heaven lost such a great judge of wisdom as Satan. He asks him why Satan came alone; surely if he told his angels he was looking for something better they would have followed.
- Satan responds, saying he's not afraid of pain. What would Gabriel know about a leader's duty to accept hardship for his followers? He has braved the dangers of exploration
- Gabriel calls Satan a liar. First he (Satan) said he was looking for pleasure and now he gives this line about being a spy of some kind? And he calls himself faithful? What a joke, says Gabriel, as he tells Satan to get back to Hell.
- Satan says Gabriel can say that once he's chained him. They stare at each other in defiance. A battle seems about to happen until God drops a pair of scales from Heaven.
- The scales weigh the alternatives of parting or fighting; parting wins out –i.e., Satan better leave or he'll be badly beaten because he's outnumbered.
- Gabriel tells Satan to take a look at the scales; Satan does, realizes there's no point, and takes off.