Dante finds himself lost in a dark, frightening wood. To regain his path, he tries to climb a mountain, but a leopard, a lion, and a wolf block his way. The Roman poet Virgil approaches him and offers to conduct him through Hell and Purgatory as the only way back to the right path. Virgil comes at the request of a lady from Heaven, Beatrice (a woman whom Dante once loved), who will guide the pilgrim through Heaven once he reaches it.
When the travelers arrive at Hell’s entrance, Virgil explains that the large group of souls outside the gates lived their lives without committing to good or evil, so neither Heaven nor Hell will accept them. At the River Acheron, where they find the ferryman Charon, Dante is seized with terror and falls unconscious. Aroused by a loud clap of thunder, he finds himself across the river and follows his guide through Limbo, the first of the nine circles of the funnel-shaped Hell. The souls in Limbo, most of whom lived in ancient times, lived virtuous lives but were not baptized (since Christ had not yet come to Earth when they lived). Unlike the other souls in Hell, they are not undergoing any torments.
The next four circles Dante and Virgil visit are reserved for those who committed sins of incontinence. In the second circle, they meet Minos, the infernal judge, who appoints newly arrived sinners to their appropriate circle for punishment. Dante is overcome by pity as he witnesses the souls who are guilty of sexual sin being eternally buffeted by a stormy wind. He speaks to two souls and faints when he hears their story. The third circle houses gluttons, who are forced to lie in muck under a constant rain of filthy hail, snow, and stagnant water and are guarded by the terrifying three-headed dog Cerberus. In the next circle, guarded by Plutus, Dante witnesses the prodigal and the avaricious in two semicircles rolling heavy boulders and clashing up against each other. Dante and Virgil reach the muddy river Styx, in which the wrathful are submerged and are tearing at one another. Dante meets someone he knows, as he does in many circles, but for the first time he feels no pity for the sinners as he begins to understand the justice of Hell’s torments. At Virgil’s signal, the ferryman Phlegyas transports them across Styx to the city of Dis.
The city of Dis, or lower Hell, encompasses the last four circles of Hell. When Dante and Virgil are denied admittance by the fallen angels who guard the city’s walls and gates, a terrified Dante wants to retrace his steps and return the way he came. However, an angel arrives from Heaven and commands the rebellious spirits to allow the two travelers passage. Once inside Dis, they discover fiery tombs that house the souls of heretics, and Dante speaks to two of the tormented. During a pause in their journey made necessary by the increasing stench from below, Virgil explains the philosophical rationale for the moral ordering of Hell’s nine circles and describes the next three.
The Minotaur—the raging half-man, half-bull—guards the seventh circle of souls who committed violence against others, against themselves, and against God. Dante and Virgil see a red river of boiling blood, in which murderers are submerged. Dante is transported by a centaur across this river to a forest and discovers that the gnarled trees there contain the souls of those who committed suicide. Next, they come to a plain of burning sand, where they find those who sinned against God (blasphemers) or nature (homosexuals and usurers). Flakes of fire rain down on all three groups. Among the homosexuals, Dante is astounded to find a former mentor, and he speaks with three souls from Florence. The two poets then come to a precipice.
To reach the eighth circle far below, Virgil summons Geryon, a frightful flying monster with a scorpion’s tail, to transport them. When they reach the bottom, they see ten moat-like ditches in descending sequence, connected by rocky bridges. Each ditch houses sinners who committed a type of fraud. Dante finds here, for instance, seducers, flatterers, diviners, sellers of political offices and favors, hypocrites, and thieves. The ten separate torments endured by frauds range from sitting in dung (flatterers) to wearing leaden coats that appear golden on the outside (hypocrites). In this circle, Dante speaks to many people and Virgil speaks to Ulysses.
Hearing a horn blow, the travelers see a group of giants buried up to their waists who surround the ninth circle, in which traitors are encased in ice. After being lowered into this final circle by the giant Antaeus, Dante converses with some of the souls there and learns the nature of their particular betrayals. At the center of this lowest circle, they see the monstrous figure of Satan, with three faces and six wings, frozen up to his waist. Climbing down his leg, they reverse direction and journey up to the earth’s surface in the opposite direction of Hell.
Dante and Virgil emerge on Easter Sunday morning from Hell’s foul air to the pure atmosphere of the Island of Purgatory, located in the unexplored Southern Hemisphere of Earth. A grassy plain surrounds a conical mountain with seven circular ledges that has an insurmountable wall around its base. They soon see a boat propelled by an angel transporting souls of recently deceased people who are destined for Heaven but who must first undergo purification. Dante recognizes a musician friend among them. As Virgil and Dante stroll through the plain, they encounter many souls who explain that they are kept in this area, ante-purgatory, because they delayed their repentance. They plead with Dante, as do many souls in this realm, to ask their families to pray for them when he returns to the Northern Hemisphere. While sleeping, Dante is transported up to the gate of Mount Purgatory by Lucia, a lady from Heaven. The angel guarding the gate inscribes seven marks with the tip of his sword on Dante’s forehead, one for each of the seven capital sins common to human beings.
Once past the gate, the two poets ascend a narrow winding path and arrive at the first ledge. They see souls bent over, carrying heavy stones on their backs. Here and on every ledge, the souls meditate on examples of the vice of which they are being cleansed and of its opposite virtue—in this case, pride and humility. As Dante climbs to the next ledge, the angel guarding the connecting stair removes the first mark on his forehead—a procedure that will be repeated from ledge to ledge. On the second ledge, the souls wear sackcloth and have their eyelids sewn shut with wire while they listen to examples of envy and generosity. The wrathful, on the next ledge, are enveloped in blinding smoke, and on the fourth ledge, Dante and Virgil witness the purging of sloth when they see souls forced to run continuously. One of the souls here asserts that human beings have free will and choose their ultimate destinies.
Virgil discusses the nature of love and the moral order of the mountain, explaining that the sinful dispositions on this mountain can be categorized as examples of misdirected, defective, or excessive love. On the fifth ledge, where avarice and prodigality are purged, the prostrate souls face the ground. Virgil and Dante are joined by the Roman poet Statius, who has completed his cleansing here and who accompanies them to the sixth ledge, where gluttony is purged by fasting. The souls on the seventh and final ledge are being cleansed of lust by fire. Afraid of being burned, Dante refuses to enter the fire until Virgil informs him that he will see his beloved Beatrice only if he walks through it.
An angel now directs the poets to a path that leads to the original Garden of Eden. As they stroll through a lovely forest, Dante comes to a stream; on the other side, a beautiful woman is gathering flowers. She tells him that this stream, Lethe, will remove his memory of sin and that another stream in the garden, Eunoe, will restore memories of good deeds. After Dante sees a procession that includes personages representing the books of the Bible, Beatrice arrives with heavenly attendants and Virgil disappears, returning to Limbo. Beatrice reproaches Dante for his unfaithfulness to her after she died, but, convinced of his sincere repentance, she agrees to lead him through Heaven.
After witnessing symbolic reenactments of church history in the garden, Beatrice and Dante rise effortlessly and instantly through the nine heavenly spheres, which are characterized by ever-increasing light and joy. Beatrice tells Dante that although the true dwelling place of all blessed souls is the Empyrean, which is outside space and time, souls appear as lights in each sphere to indicate to him their different degrees of blessedness. On the sphere of the Moon, Dante finds those who were forced to break their vows of chastity in religious life. Here, as elsewhere in Heaven, Dante asks many questions, and Beatrice or another blessed soul answers him. Beatrice then leads him to Mercury, where he sees the souls of those who were interested in their own glory and hears Justinian narrate a survey of the history of the Roman Empire. From there, they rise to Venus, where Dante converses with souls whose lives were marked by excessive passions.
Arriving at the fourth sphere, the Sun, Dante and Beatrice are encircled by a group of lights representing the great theologians. As spokesman, Thomas Aquinas, a Dominican friar, names and comments on each of the souls and narrates the life of Saint Francis of Assisi. A second circle of lights surrounds the first, and a new spokesman, Bonaventure, a Franciscan friar, narrates the life of Saint Dominic and then names the souls in that second circle.
When Beatrice and Dante rise to Mars, the fifth sphere, they see crusaders and martyrs, who appear as sparks in the shape of a cross. Dante meets his ancestor Cacciaguida, who commissions him to report all that he has seen when he returns to Earth and warns him that he will be driven into exile in the future. Next, on Jupiter, Dante sees the souls of those who administered justice faithfully, such as King David and Charlemagne, who appear in the shape of an eagle’s head and neck. In the seventh sphere, Saturn, Dante finds the great contemplatives such as Saint Benedict.
When they arrive at the sphere of fixed stars, Dante looks down on the earth and is astonished by its insignificance with respect to the cosmos. He undergoes examinations by the apostles Peter, James, and John on faith, hope, and love to see if he is properly prepared to enter the Empyrean. Adam approaches the group and tells Dante about his brief time in the Garden of Eden. Peter bitterly laments the corruption in the Church and commissions Dante to repeat what he has just heard when he returns to Earth.
In the ninth sphere, Dante sees God as a point of light encircled by the nine orders of angels who rotate all the lower spheres. Beatrice then leads him into the Empyrean, where he first sees symbolic visions of Heaven’s assembly and is strengthened thereby to see it in its true form, which he compares to a white rose. After realizing that Beatrice has returned to her heavenly seat, Dante sees an old man at his side, Bernard of Clairvaux, a medieval mystic, who prays for his final vision of God. Dante sees God first as light, then as three rainbow-colored rings, representing the Trinity; his culminating vision is of humanity’s union with God in Christ.