Inferno tells of Dante's descent, while still alive, through the nine circles of the realm of the damned, guided by the Roman poet Virgil, to the center of the Earth, where Lucifer is held in the ice, and of the exit on the other side, back to the stars. The action is dated to Holy Week of 1300, and the poem is told afterward, in the first person, by Dante himself.
In the first cantos, Dante, midway along the path of life, finds himself in a dark wood without knowing how he entered it; he is blocked by a leopard, a lion and a she-wolf on the slope of a hill, and is helped by Virgil, who proposes another path. Beatrice, who came down from heaven, is the reason for the journey. The two cross the gate of Hell and arrive at Limbo, the first circle.
The descent follows the order Virgil sets out in Canto XI. First come the sins of desire: lust, gluttony, avarice and wrath; then violence, in the river of blood, the wood of the suicides and the sand of fire; then fraud, in the ten ditches of Malebolge; and at the bottom treachery, in the ice of Cocytus. Along the way Dante talks with condemned souls such as Francesca, Farinata, Brunetto Latini, Ulysses and Ugolino, and many of them announce what will happen to him and to Florence.
In Canto XXXIV, Virgil and Dante descend through the body of Lucifer, the descent turns into an ascent at the center of the Earth, and they leave through a round hole to see the stars again.