Travel to The Undercity (the southern entrance northeast of Nahpui Quarter is closest). Once inside the Undercity go right, turn the corner, then head east. The quest marker will lead to two Am Fah Bandits talking. Do not attack them until the quest updates. After they are done talking, you may kill them, then proceed east. After passing Mina Shatter Storm and his group, you will come across two small groups of Am Fah accompanied by an Am Fah Leader. The leader will drop the Orrian Tome when slain. Take it back to the minister for your reward.