The Odyssey is 12,109 lines composed in dactylic hexameter, also called Homeric hexameter. It opens in medias res, in the middle of the overall story, with prior events described through flashbacks and storytelling. The 24 books correspond to the letters of the Greek alphabet; the division was likely made after the poem's composition by someone other than Homer, but is generally accepted.
In the Classical period, some of the books (individually and in groups) were commonly given their own titles:
- Book 1–4: Telemachy —the story focuses on the perspective of Telemachus.
- Books 9–21: Apologoi—Odysseus recalls his adventures for his Phaeacian hosts.
- Book 22: Mnesterophonia ('slaughter of the suitors'; Mnesteres, 'suitors' + phónos, 'slaughter').
Book 22 concludes the Greek Epic Cycle, though fragments remain of the "alternative ending" of sorts known as the Telegony. The Telegony aside, the last 548 lines of the Odyssey, corresponding to Book 24, are believed by many scholars to have been added by a slightly later poet.