Dante finds himself lost in a dark forest at the midpoint of his life, struggling to find the right path. When he attempts to climb a sunlit hill, his way is blocked by three fierce beasts: a leopard, a lion, and a she-wolf. Overwhelmed by fear and driven back into the shadows, he is met by the shade of the ancient Roman poet Virgil. Virgil offers to guide him along an alternative route that leads away from the wilderness through the eternal realms of the afterlife, explaining that a hound will eventually appear to drive the she-wolf back into hell. Hearing this, Dante willingly follows Virgil as his master and leader.
As twilight falls, Dante experiences a moment of doubt regarding his worthiness to undertake such a journey, comparing himself unfavourably to figures like Aeneas and Saint Paul. Virgil reassures him by revealing that he was sent by Beatrice, a blessed lady in heaven who was moved by divine compassion. Beatrice had descended to Limbo to enlist Virgil, after being urged by Saint Lucia, who was herself prompted by the Virgin Mary's concern for Dante's spiritual peril. Reinvigorated by this heavenly intervention and Beatrice's love, Dante casts off his fear and officially accepts Virgil as his guide.
The two poets arrive at the gates of hell, reading the ominous inscription that warns those who enter to abandon all hope. Inside, they encounter the souls of the indifferent and neutral angels who took neither side in the rebellion against God. Unwanted by heaven and rejected by hell, these wretched souls run endlessly behind a spinning banner while being stung by wasps and hornets, their suffering compounded by the fact that they are completely forgotten by the living world. Virgil and Dante then approach the banks of the river Acheron, where the ferryman Charon angrily attempts to bar Dante from passing because he is still alive. After Virgil quiets the boatman by invoking divine will, the weary, wailing crowds of damned souls hurl themselves into the boat to cross the dark water, and an earthquake causes Dante to faint.
Awakening from his stupor, Dante finds himself on the brink of the abyss in the first circle of hell, known as Limbo. Here reside the unbaptized and the virtuous pagans who lived before Christ, who suffer no physical torment but live in perpetual desire without hope, mourning their separation from God. Among them is Virgil himself. When Dante asks if anyone has ever left this place, Virgil relates how a mighty conqueror bearing the sign of victory descended into hell to rescue the souls of the patriarchs, including Adam, Abel, Noah, Moses, and Abraham. Moving deeper into Limbo, the pair encounters a group of great classical poets—Homer, Horace, Ovid, and Lucan—who welcome Dante into their noble company as the sixth member of their scholarly group.
They lead him to a magnificent castle surrounded by seven walls and a fresh stream, where Dante is shown a gathering of great heroes, heroines, philosophers, and scientists of antiquity, including Aristotle, Socrates, Plato, Julius Caesar, and Saladin.
Leaving the noble castle, Virgil and Dante descend into the second circle of hell, which is much smaller but vastly more agonizing. At the entrance stands Minos, the monstrous judge of the dead, who examines every arriving soul and assigns them to their proper torment by wrapping his tail around his body. Recognizing Dante, Minos warns him against entering, but Virgil silences him with the same divine formula used previously. In this dark realm, a relentless infernal storm buffets the carnal sinners who surrendered reason to lust, whirling them mercilessly through the air and dashing them against the rocks. Virgil points out famous lovers of antiquity, including Semiramis, Dido, Cleopatra, Helen, Achilles, Paris, and Tristan. Moved by profound pity, Dante calls out to two souls drifting together—Paolo and Francesca—who break away from their flock like homing doves to speak with him.
Francesca recounts their tragic love story, explaining how reading of Lancelot kindled their passion, how love spared no beloved from loving in return, and how they were ultimately murdered by her husband, leaving Dante so overwhelmed with sorrow that he faints once more.