To the Undercity for Yagyin's Digest:

Bring the Sigil of the Hammer to Keeper Bel'dugur in the Undercity.

Theldurin the Lost: The tablet tells much. But not enough! Not nearly enough!

There is a book, a digest that Yagyin wrote in ages past. The... people I fled from... they keep this book in many places. And their most learned study it. It holds vast knowledge. Knowledge to protect us!

Go to Keeper Bel'dugur in the Undercity of Lordaeron. Show him this sigil and he'll think you one of them. Ask him for Yagin's Digest...and bring it to me!

Keeper Bel'dugur: Ah, we have an eager shaman, I see. Are you here to learn from my collection? Good!

But be warned: just as knowledge gives power to the strong...it will drive the weak mad.

Keeper Bel'dugur: Be discrete with your signs, shaman. There are those who do not believe the righteousness of our pledge.

And there are those who would see us fail if they knew of us.

We must always be careful. And watchful. And patient.