The Purgatorio is the second book in the three-part Divine Comedy by the 14th-century Italian poet Dante Alighieri. After the first book, the Inferno, which tours hell, the Purgatorio tells the story of Dante's travels through purgatory. Virgil eventually passes Dante off to Beatrice, but before then, they travel up the the seven layers of punishment and spiritual correction of sins before they can come to the Earthly Paradise. Purgatory is depicted as a mountain in the Southern Hemisphere with tiers for correcting each of the seven deadly sins.
If you're bored by traditional book notes, try Shmoop! They write their summaries in an approachable, entertaining style. Their comprehensive offering includes chapter by chapter summaries, themes, quotes, character analysis, study quizzes, and even flash cards and infographics.