Wondrous item, artifact (requires attunement by a wizard) • When casting divination spells, you don't require any material components.
• You gain a +3 bonus to AC.
• You may cast the augury spell once per day. • You may cast the hunter's mark spell three times per day.
"They were a collection of oracular utterances, set out in Greek hexameters, that according to tradition were purchased from a sibyl by the last king of Rome, Tarquinius Superbus, and were consulted at momentous crises through the history of the Republic and the Empire."