Paradiso opens with Dante's invocation to Apollo and the Muses, asking for his divine task. He and Beatrice ascend from the Earthly Paradise. Beatrice outlines the structure of the universe. Dante warns the readers not to follow him now into Heaven for fear of getting lost in the turbulent waters.
Dante and Beatrice arrive in the First Heaven, sphere of the Moon. Beatrice vigorously quizzes Dante and then corrects his views on the cause of the moon spots. Dante first sees the blessed souls as points of light. He meets Piccarda Donati, who explains the souls' happiness with their places in Heaven. She explains that the Moon houses souls who broke their vows. Beatrice explains why Dante sees the souls in these heavens, when they are all located in the Empyrean, (the Tenth Heaven). Then she explains vows in terms of absolute and contingent will.
They ascend to the Second Heaven, sphere of Mercury. Justinian explains the history and destiny of Rome. He tells Dante that the souls in Mercury were all just, but motivated by fame. Beatrice explains God's just vengeance on Jerusalem.
They ascend to the Third Heaven, sphere of Venus. Dante meets Charles Martel, an early French emperor, and he explains why sons can end up so different from their fathers. Dante meets Cunizza da Romano and Folco of Marseille, who points out Rahab to Dante.
Beatrice and Dante ascend to the Fourth Heaven, sphere of the Sun. St. Thomas and eleven other souls form a crown around our heroes. Dante denounces the senseless cares of mortals. St. Thomas discusses the life of St. Francis and the Franciscans. A second crown forms around the first. St Bonaventure talks about the life of St. Dominic and the Dominicans. The crowns dance. St. Thomas explains the wisdom of King Solomon and warns Dante not to judge hastily. Solomon explains the source of the blessed souls' light.
They ascend to the Fifth Heaven, sphere of Mars. The souls form an image of the Cross. Dante meets Cacciaguida, who expounds on the virtue of ancient Florence. Dante indulges in a rare proud moment over the nobility of his birth. Cacciaguida talks about the noble Florentine families. Then, he tells Dante about his destiny of exile, but tempers it with encouragement to Dante to fulfill his poetic mission.
Dante and Beatrice move on to the Sixth Heaven, sphere of Jupiter. The souls spell out the message Diligite iustitiam, qui iudicatis terram ("Love justice, you who judge the earth"), and then form the Eagle. The Eagle explains Divine Justice and the inscrutability of God's Mind. It introduces the six spirits that form its eye and explains why the Emperor Trajan and Ripheus are there.
They continue to the Seventh Heaven, sphere of Saturn. Dante sees the golden ladder. Dante meets St. Peter Damian, who denounces degenerate prelates. The spirits cry out in encouragement and Dante faints from the force. Dante meets St. Benedict.
Beatrice and Dante ascend to the Eighth Heaven, sphere of the Fixed Stars. Dante gazes down on Earth and realizes how small and petty it is. They witness the coronation and re-ascension of Mary and Christ into the Empyrean. St. Peter examines Dante on faith. Dante conveys his hope of returning to Florence one day to be crowned as a poet. St. James examines Dante on hope. Dante goes blind. St. John examines Dante on charity. Adam answers Dante's four questions. St. Peter denounces corrupt popes.
Beatrice and Dante then move on to the Ninth Heaven, Primum Mobile. Beatrice prophesies the coming redemption of the world. Dante observes the model of the nine Angelic Intelligences orbiting a shining Point. Beatrice explains the discrepancy between it and the material universe. Beatrice tells Dante the Creation story, explains the order of the universe, and clears up the question about the number of extant angels.
They ascend into the Tenth Heaven, the Empyrean. Dante sees the illusion and then real Celestial Rose. Beatrice points out the seat reserved for Henry VIII. Beatrice disappears and is replaced by St. Bernard. Dante prays his thanks to Beatrice.
Next, Dante gazes upon Mary. St. Bernard explains the placement of the blessed in the Celestial Rose, including that of the innocent infants. St. Bernard prays to Mary to intercede to God on Dante's behalf so that the poet may look upon God. Mary approves. Dante looks into the Eternal Light, and sees within it the image of the Holy Trinity. He ponders the mystery of the Incarnation. God bestows the answer upon him in a flash of light and Dante's soul is, finally, at one with God's.