The poem starts on Maundy Thursday in the year 1300. The narrator, Dante himself, is thirty-five years old, and thus "halfway along our life's path" (Nel mezzo del cammin di nostra vita) – half of the Biblical lifespan of seventy (Psalms 89:10, Vulgate). The poet finds himself lost in a dark wood in front of a mountain, assailed by three beasts (a lion, a lonza [usually rendered as "leopard" or "leopon"], and a she-wolf) he cannot evade. Unable to find the "straight way" (diritta via, also translatable as "right way") to salvation, he is conscious that he is ruining himself and falling into a "deep place" (basso loco) where the sun is silent (l sol tace).
Dante is at last rescued by the Roman poet Virgil, who claims to have been sent by Beatrice, and the two of them begin their journey to the underworld. Each sin's punishment in Inferno is a contrapasso, a symbolic instance of poetic justice; for example, fortune-tellers have to walk forward with their heads on backward, unable to see what is ahead, because they tried to see the future through forbidden means. Such a contrapasso "functions not merely as a form of divine revenge, but rather as the fulfilment of a destiny freely chosen by each soul during his or her life."
Dante passes through the gate of Hell, which bears an inscription, the ninth (and final) line of which is the famous phrase "Lasciate ogne speranza, voi ch'intrate", or "Abandon all hope, ye who enter here."
Before entering Hell completely, Dante and his guide see the Uncommitted, souls of people who in life did nothing, neither for good nor evil; among these Dante recognizes either Pope Celestine V or Pontius Pilate (the text is ambiguous). Mixed with them are outcasts who took no side in the Rebellion of Angels. These souls are neither in Hell nor out of it, but reside on the shores of the Acheron, their punishment to eternally pursue a banner (i.e. self interest) while pursued by wasps andhornets that continually sting them as maggots and other such insects drink their blood and tears. This symbolizes the sting of their conscience and the repugnance of sin. This can also be seen as a reflection of the spiritual stagnation they lived in. As with the Purgatorio and Paradiso, the Inferno has a structure of 9+1=10, with this "vestibule" different in nature from the nine circles of Hell, and separated from them by the Acheron.
Virgil is traditionally ranked as one of Rome's greatest poets. His Aeneid has been considered the national epic of ancient Rome from the time of its composition to the present day. Modeled after Homer's Iliad and Odyssey, theAeneid follows the Trojan refugee Aeneas as he struggles to fulfill his destiny and arrive on the shores of Italy—in Roman mythology the founding act of Rome. Virgil's work has had wide and deep influence on Western literature, most notably Dante's Divine Comedy, in which Virgil appears as Dante's guide through hell and purgatory.
The words of Dante:
"When I had journeyed half of our life's way, I found myself within a shadowed forest,
for I had lost the path that does not stray."
Their sighs, lamentations and loud wailings
resounded through the starless air,
so that at first it made me weep;
Strange utterances, horrible pronouncements,
words of pain, tones of anger,
voices shrill and faint, and beating hands,
all went to make a tumult that will whirl
forever through that turbid, timeless air,
like sand that eddies when a whirlwind swirls.