Once you loot the Sealed Tome of Lost Legion you must combine it with a Healthstone to create “The Codex of Xerrath“. This item begins a quest titled “The Unusual Tome“.

The Codex of Xerrath has a very low drop rate from killing the Krasarang Wilds Patch 5.1 Landfall mobs. Check out the official World of Warcraft website to see which mobs drop it.

It’s said the Sealed Tome of the Lost Legion will drop from Isle of Thunder mobs and elite mobs, too.

Black Temple exterior