It is early spring in the year 1300, and Dante, "midway along the road of our life," has strayed from the straight path and finds himself in a dark wood. Heartened by the sight of a sunlit hill, he begins to climb to safety, but soon he is beset by a leopard, a lion, and a she-wolf and forced to retreat to the valley. Here Dante meets the shade of Virgil the great Roman poet; to escape his dire predicament, Dante must visit the three realms of the afterlife, beginning with Hell, eternal abode of lost souls.

The dark forest—selva oscura—in which Dante finds himself at the beginning of the poem (Inf. 1.2) is described in vague terms, perhaps as an indication of the protagonist's own disorientation. The precise nature of this disorientation—spiritual, physical, psychological, moral, political—is itself difficult to determine at this point and thus underscores two very important ideas for reading this poem: first, we are encouraged to identify with Dante (the character) and understand knowledge to be a learning process; second, the poem is carefully structured so that we must sometimes read "backwards" from later events to gain a fuller understanding of what happened earlier.

Characteristic of Dante's way of working, this "dark wood" is a product of the poet's imagination likely based on ideas from various traditions. These include the medieval Platonic image of chaotic matter—unformed, unnamed—as a type of primordial wood (silva); the forest at the entrance to the classical underworld (Hades) as described by Virgil (Aeneid 6.179); Augustine's association of spiritual error (sin) with a "region of unlikeness" (Confessions 7.10); and the dangerous forests from which the wandering knights of medieval Romances must extricate themselves. In an earlier work (Convivio 4.24.12), Dante imagines the bewildering period of adolescence—in which one needs guidance to keep from losing the "good way"—as a sort of "meandering forest" (erronea selva).

Awakening on the other shore of Acheron, Dante follows Virgil into Limbo, the first circle of Hell. Limbo is set apart from the rest of Hell by its tranquil, pleasant atmosphere. It is the eternal abode of spirits from the pre-Christian world who led honorable lives, as well as other worthy non-Christian adults and the souls of unbaptized children. Virgil is welcomed back to his home in a "noble castle" by a select group of classical poets, headed by Homer. Dante joins this prestigious company and sees other famous figures from the ancient world (both historical and literary) - among them Plato, Aristotle, Pythagoras, Aeneas, Cicero, and Julius Caesar - and prominent medieval non-Christians.

The concept of Limbo, a region on the edge of Hell (limbus mean "hem" or "border") for those who are not saved even though they did not sin, existed in Christian theology prior to Dante, but Dante's Limbo (technically the first circle of Hell) is more generous than most, including virtuous non-Christian adults in addition to unbaptized infants. We find there many great heroes, thinkers, and creative minds of ancient Greece and Rome, as well as such non-Christians as Saladin, sultan of Egypt in the late twelfth century, and the Islamic philosophers Avicenna (Ibn Sina) and Averroes (Ibn Rushd). For Dante, Limbo had also been home to major figures from the Hebrew Bible, until, as described in the following entry, they were "liberated" by Jesus Christ following his crucifixion.

Dante and Virgil encounter Minos, the monster who judges all the souls damned to Hell, at the entrance to the second circle. Tossed about by vicious winds, the spirits within this circle are guilty of lust, a sin that for many led to adultery and, for at least some of the most famous - Dido, Cleopatra, Helen of Troy, Achilles, Paris and Tristan - to a violent death. Dante is drawn to two lustful souls still bound to one another in Hell: the beautiful Francesca and her handsome brother-in-law Paolo were murdered by the betrayed husband. Dante is so distraught after hearing Francesca's moving tale of how she a Paolo came to act on their passion that he faints and falls hard to the ground.

Here Dante explores the relationship—as notoriously challenging in his time and place as in ours—between love and lust, between the ennobling power of attraction toward the beauty of a whole person and the destructive force of possessive sexual desire. The lustful in hell, whose actions often led them and their lovers to death, are "carnal sinners who subordinate reason to desire" (Inf. 5.38-9). From the examples presented, it appears that for Dante the line separating lust from love is crossed when one acts on this misguided desire. Dante, more convincingly than most moralists and theologians, shows that this line is a very fine one indeed, and he acknowledges the potential complicity (his own included) of those who promulgate ideas and images of romantic love through their creative work. Dante's location of lust—one of the seven capital sins—in the first circle of hell in which an unrepented sin is punished (the second circle overall) is similarly ambiguous: on the one hand, lust's foremost location—farthest from Satan—marks it as the least serious sin in hell (and in life); on the other hand, Dante's choice of lust as the first sin presented recalls the common—if crude—association of sex with original sin, that is, with the fall of humankind (Adam and Eve) in the garden of Eden.

Cerberus, a doglike beast with three heads, guards the third circle of Hell and mauls the spirits punished here for their gluttony. The shades, writing in muck, are unrelentingly pounded by a cold and filthy mixture of rain, sleet, and snow that makes the earth stink. One glutton, nicknamed Ciacco, rises up and recognizes Dante as a fellow Florentine. Ciacco prophesies bloody fighting between Florence's two political factions that will result in the supremacy of one party (white Guelphs) and then, less than three years later, the victory and harsh retribution of the other party (black Guelphs). After informing Dante that several leading Florentines are punished below in other circles of Hell, Ciacco falls back to the ground not to rise again until the Last Judgment at the end of time.

Gluttony, like lust, is one of the seven capital sins according to the medieval Christian theology and church practice. Dante, at least in circles two through five, uses these sins as part (but only part) of his organizational strategy. Although lust and gluttony were generally considered the least serious of the seven sins (and pride almost always the worst), their ranking not consistent: some writers thought lust was worse than gluttony, while others thought gluttony worst than lust. Based on the biblical precedent of Eve eating the forbidden fruit and then tempting Adam to do so (Genesis 3:6), gluttony and lust were often viewed as closely related. Gluttony is usually understood as referring to excessive eating and drinking; from the less than obvious contrapasso for the gluttons and the content (mostly political) of Inferno 6, Dante appears to view it as something more complex.

Plutus, a wolflike beast, shouts a warning to Satan as Dante and Virgil enter the fourth circle of Hell, but Virgil's harsh rebuke silences him and allows the travelers to pass unscathed. Dante now sees a multitude of shades damned for the sin of avarice (holding wealth too tightly) or its opposite prodigality (spending too freely). The two groups push heavy boulders with their chests around a circle in opposite directions: when the avaricious and the prodigal collide, they turn and, after casting insults at one another, repeat the journey in the other direction. So filthy have the souls come as a result of their sordid lives hat Dante cannot recognize them individually, though Virgil reports the presence of many clerics, including cardinals and popes, among the avaricious. He also explains to Dante the divine role of Fortuna in human affairs.

Avarice—greed, lust for material gain—is one of the iniquities that most incurs Dante's scornful wrath. Consistent with the biblical saying that avarice is "the root of all evils" (1 Timothy 6:10), medieval Christian thought viewed the sin as most offensive to the spirit of love; Dante goes even further in blaming avarice for ethical and political corruption in his society. Ciacco identifies avarice—along with pride and envy—as one of the primary vices enflaming Florentine hearts (Inf. 6.74-5), and the poet consistently condemns greed and its effects throughout The Divine Comedy. Dante accordingly shows no mercy—unlike his attitude toward Francesca (lust) and Ciacco (gluttony)—in his selection of avarice as the capital sin punished in the fourth circle of hell (Inferno 7). He viciously presents the sin as a common vice of monks and church leaders (including cardinals and popes), and he further degrades the sinners by making them so physically squalid that they are unrecognizable to the travelers (Inf. 7.49-54). By defining the sin as "spending without measure" (7.42), Dante for the first time applies the classical principle of moderation (or the "golden mean") to criticize excessive desire for a neutral object in both one direction ("closed fists": avarice) and the other (spending too freely: prodigality). Fittingly, these two groups punish and insult one another in the afterlife.

Dante sees wrathful souls battering and biting one another in the swampy waters of the Styx, the fifth circle of Hell, and he learns that the bubbles on the surface are caused by sullen spirits stuck in the muddy bottom of the marsh. The travelers cross the Styx n a swift vessel piloted by Phlegyas. When Filipo Argenti, an arrogant Florentine whom Dante knows and detests, rises up and threatens to grab the boat, Virgil shoves him back into the water, where he is slaughtered by his wrathful cohorts, much to Dante's delight. The resentful boatman deposits Dante and Virgil at the entrance to Dis, the fortressed city of Lower Hell. Over a thousand fallen angels who guard the entrance refuse entry to the travelers, slamming the gate in Virgil's face. Bloodcurdling Furies then appear above the walls and call on Medusa to come and turn Dante to stone. However, a messenger from Heaven arrives to squelch the resistance and open the gate, thus allowing Dante and Virgil to visit the circles of Lower Hell.

Like the fourth circle of Hell, circle five contains two related groups of sinners. But whereas avarice and prodigality are distinct sins based on the same principle (an immoderate attitude toward material wealth), wrath and sullenness are basically two forms of a single sin: anger that is expressed (wrath) and anger that is repressed (sullenness). This idea that anger takes various forms is common in ancient and medieval thought. The two groups suffer different punishments appropriate to their type of anger: the wrathful endlessly attack one another while the sullen stew below the surface of the swamp (Inf. 7.109 -26), even as they are all confined to Styx.

Dante designates all of Lower Hell - circles six through nine, where more serious sins are punished - as the walled city of Dis (Inf. 8.68), one of the names for the kind of the classical underworld (Pluto) and, by extension, the underworld in general. For Dante, then, Dis stands both for Lucifer and the lower circles of his infernal realm. It may be significant that Virgil, who repeatedly refers to Dis in his Aeneid (eg., 4.702, 5.731, 6.127, 6.269), is the one who announces the travelers' approach to Dis in The Divine Comedy. Details of the city and its surroundings - including moats, watchtowers, high walls, and a well-guarded entrance (Inf. 8-9) - suggest a citizenry ready for battle.

After passing through the walls of Dis, Virgil leads Dante across the sixth circle of Hell, a vast plain resembling a cemetery. Stone tombs, raised above the ground with their lids removed, glow red from the heat of flames. Buried in these sepulchers are the souls of heretic, each tomb holding an untold number of individuals who adhered to the broadest notion of heresy: denial of the soul's immortality. Dante sees standing upright in one tomb the imposing figure of Farinata, a Florentine leader of Ghibellines, the political party bitterly opposed to the party of Dante's ancestors. Peering out from the same tomb is the father of Dante's best friend; Cavalcante is upset that his son Guido is not with Dante on the journey. Here Dante learns, as the result of a misunderstanding, that the damned possess the power to see the future but not the present. Needing time to adjust to the stench wafting up from the lower circles, the travelers take refuge behind the tomb of a heretical pope. Virgil uses this time to describe the overall layout of Hell and the reasons for this organization.

Dante opts the most generic conception of heresy - the denial of the soul's immortality (Inf. 10.15) - perhaps in deference to the spiritual and philosophical positions of specific characters he wishes to feature here, or perhaps for the opportunity to present an especially effective form of contrapasso: heretical souls eternally tormented in fiery tombs. More commonly, heresy in the Middle Ages was a product of acrimonious disputes over Christian doctrine, in particular the theologically correct ways of understanding the Trinity and Christ. Crusades were waged against "heretical sects," and individuals accused of other crimes or sins (such as witchcraft, usury, and sodomy) were frequently labeled heretics as well.

Heresy, according to a theological argument based on the dividing of Jesus's tunic by Roman soldiers (Matthew 27:35), was traditionally viewed as an act of division, a symbolic laceration in the community of "true" believers. This may help explain why divisive, partisan politics is such a prominent theme in Dante's encounter with Farinata. Umberto Eco's best-selling novel The Name of the Rose (1980), set in a northern Italian monastery only a few decades after the time of Dante's poem (and made into a film in 1986), provides a learned and entertaining portrayal of heretics and their persecutors.

After slipping by the Minotaur, Dante and Virgil visit the three areas of circle seven, where the violent shades are punished. Astride the Centaur Nessus, Dante views those who committed violent acts against fellow human beings, from ruthless tyrants and warriors (such as Attila the Hun) to murderers and highway bandits, all submerged to an appropriate depth in a river of boiling blood. The travelers then enter a forest whose gnarled and stunted trees are the souls of suicides. Harpies inflict pain on the suicide-tress by feeding on their leaves, while the wounds created by the Harpies' gnawing provide an outlet for this pain. Here Dante is moved by the tale of Pier della Vigna, he sees men who squandered their wealth chased and dismembered by ferocious black dogs. Dante and Virgil next cross a desert scorched by rain and fire, which punishes violent offenders against God: blasphemers flat on their backs (including Capaneus, a defiant classical warrior); sodomites in continuous movement (among these Bruentto Latini, Dante's beloved teacher); and usurers crouching on the ground with purses, decorated with their families' coats of arms hanging from their necks. Dante and Virgil descend to the next circle aboard Geryon, a creature with a human face, reptilian body, and scorpion's tail.

Virgil explains to Dante that sins of violence are categorized according to the victim: other people (one's neighbor) oneself, or God (Inf. 11.28-33). Those who perpetrate violence against other people or their property (murderers and bandits) are punished in the first ring of the seventh circle, a river of blood (Inf. 12). Those who do violence against themselves or their own property - suicides and squanderers (more self-destructive than the prodigal in circle of our)-inhabit the second ring, a horrid forest (Inf. 12). The third ring, enclosed by the first two, is a barren plain of sand ignited by flakes of fire. These torment three separate groups of violent offenders against God: those who offend God directly (blasphemers, Inferno 14); those who violate nature, God's offspring (sodomites; Inferno 15-16); and those who harm industry and the economy, offspring of nature and therefore grandchild of God (usurers; Inferno 17). Associating the sins of these last two groups with Sodom and Cahors (Inf. 11.49-50), Dante draws on the biblical destruction of Sodom and (and Gomorrah) by fire and brimstone (Genesis 19:24-25) and medieval depictions of citizens of Cahors (a city in southern France) as usurers. Dante's emotional reaction to the shades in the seventh circle range from neutral observation of the murderers and compassion for a suicide to respect for several Florentine sodomites and revulsion at the sight and behavior of lewd usurers.

The offenses punished in circles eight and nine, the two lowest circles of Hell, all fall under the rubric of fraud, a form of malice (as Virgil explains in Inferno 11.22-27) unique to human beings and therefore more displeasing to God than sins of concupiscence and violence (Circle 7). All versions of fraud involve the malicious use of reason; what distinguishes circle eight from circle 9 is the perpetrator's relationship to his or her victim: if there exists no bond besides the "natural" one common to all humanity, the guilty soul suffers in one of the ten concentric ditches that constitute circle eight, but those who betray an individual or group with whom they share a special bond of trust (family, political party or homeland, guests, benefactors) are punished in the lowest circle.

Physically connected by bridges, the ditches of circle 8 contain fraudulent shades whose particular vices and actions similarly serve to interconnect the cantos and their themes in this part of the poem. Thus the pimps and seducers, whipped by horned demons in the first ditch, relate to the flatterers—disgustingly dipped in the excrement of the second ditch—through the sexualized figure of Thais, a prostitute from the classical tradition who falsely praises her "lover" (Inf. 18.127-35). These first two ditches are presented in a single canto (18). Images of degraded sexuality are even more prominent in the next canto (19). Here Dante presents simony—the abuse of power within the church—as a form of spiritual prostitution, fornication, and rape (Inf. 19.1-4; 55-7; 106-11), a perversion of the holy matrimony conventionally posited between Christ (groom) and the church (bride). Simon Magus, the man for whom simony is named (Inf. 19.1), was himself a magician or sorcerer, the profession of those punished in the fourth ditch (canto 20).

Simony and Sorcery are further linked through biographical declarations—by Dante and Virgil, respectively—aimed at separating truth from falsehood: Dante sets the record straight when he announces that he shattered a marble baptismal basin to prevent someone from drowning in it (Inf. 19.19-21); and Virgil is equally emphatic that his native city, Mantua, was named after the prophetess Manto with no recourse to such dubious rituals as casting lots or interpreting signs (Inf. 20.91-3; 97-9). Political corruption (fifth ditch), the crime for which Dante himself was falsely charged when he was forced into exile, links back to similar abuses within the church (simony) and points ahead to the sin of hypocrisy. The longest single episode of the Inferno, launched when Virgil confidently believes the promise of the devils guarding the fifth ditch, concludes when the travelers make a narrow escape into the sixth ditch and Virgil learns from a hypocrite that he has been duped (Inf. 23.133-48). Dante adorns the hypocrites in religious garb—hooded cloaks similar to the elegant ones worn by the Benedictine monks at Cluny (in France)—in accordance with the biblical condemnation of false piety: just as Jesus compares hypocritical scribes and Pharisees to tombs that appear clean and beautiful on the outside while containing bones of the dead (Matthew 23:27), so the bright golden cloaks of Dante's hypocrites conceal heavy lead on the inside (Inf. 23.64-6).

Towering over the inner edge of circle eight are Giants, one of whom (Antaeus) lowers Dante and Virgil onto the frozen surface of Cocytus, the ninth circle of Hell. Embedded in separate regions of the ice are those who betrayed kind (Caina), homeland or political party (Antenora), guests (Ptolomea), and benefactors (Judecca). After kicking one of the political traitors hard in the face, Dante learns that is man (Bocca) betrayed the Florentine Guelphs at Montaperti. In the same region Dante finds Count Ugolino gnawing on the skull of Archbishop Ruggieri, whose cruelty cause Ugolino (with his sons and grandsons) to die of hunger. Fra Alberigo informs Dante that the souls of those who betray their guests arrive in Hell even while their bodies continue to live on Earth. In Judecca, at the very center of Hell, Dante sees Lucifer. Much larger than the giants, he has three hideous faces and six huge, batlike wings that generate the winds needed to keep the lake frozen. Two mouths, one on each side, chew on Caesar's assassins, Brutus, and Cassius, while the middle mouth engulfs Judas, the betrayer of Jesus. Virgil carries Dante down the shaggy body of Lucifer, making sure to flip over and climb once they have passed through the center of Earth. Dante then follow Virgil along a trailer through the other half of the globe until he is able to see again the stars.

Dante divides circle 9, the circle of treachery—defined in Inferno 11 as fraudulent acts between individuals who share special bonds of love and trust (61-6)—into four regions. Caina is named after the biblical Cain (first child of Adam and Eve), who slew his brother Abel out of envy after God showed appreciation for Abel's sacrificial offering but not Cain's (Genesis 4:1-17); condemned to a vagabond existence, Cain later built a city (named after his son, Henoch) that for certain Christian theologians—notably Augustine (City of God, book 15)—represented the evils of the earthly city. In the circle of the lustful, Francesca identified her husband (Gianciotto)—who murdered her and Paolo (Gianciotto's brother)—as a future inhabitant of Caina (Inf. 5.107). Dante's attention is here drawn to two brothers, the Ghibelline Napoleone and the Guelph Alessandro, who murdered one another because of a dispute over their inheritance (Inf. 32.55-60).

The second region, Antenora, is named for the Trojan prince Antenor. While the classical sources—notably Homer's Iliad—present Antenor in a positive (or at least neutral) light as one in favor of returning Helen to the Greeks for the good of Troy, medieval versions—histories, commentaries, and romances—view him as a "treacherous Judas" who plots with the Greeks to destroy the city. Dante places in this region those who betrayed their political party or their homeland.

In the third zone of circle 9 suffer those who betrayed friends or guests. Ptolomea is named after one or both of the following: Ptolemy, the captain of Jericho, honored his father-in-law, the high priest Simon Maccabee, and two of Simon's sons with a great feast and then murdered them (1 Maccabees 16:11-17); Ptolemy XII, brother of Cleopatra, arranged that the Roman general Pompey—seeking refuge following his defeat at the battle of Pharsalia (48 B.C.E.)—be murdered as soon as he stepped ashore. Dante displays his abhorrence of such crimes by devising a special rule for those who betray their guests: their souls descend immediately to hell and their living bodies are possessed by demons when they commit these acts (Inf. 33.121-6).

Judecca, named after the apostle who betrayed Jesus (Judas Iscariot), is the innermost zone of the ninth and final circle of hell. The term also hints at a manifestation of Christian prejudice—which Dante certainly shares—against Judaism and Jews in the Middle Ages: it alludes to the names—Iudeca, Judaica—for the area within certain cities (e.g., Venice) where Jews were forced to live, apart from the Christian population. Together with Judas in this region of hell are others who, by betraying their masters or benefactors, committed crimes with great historical and societal consequences. Completely covered by the ice—like "straw in glass"—the shades are locked in various postures with no mobility or sound whatsoever (Inf. 34.10-15).