From the Hollow Victory event.

The beautiful city of Xarabydun lies beneath the desert sands. But even lower still lies the remains of an old library, now a breeding ground for K'naths.

The rumor for this quest can be purchased from the barkeep Mausin ibn Hi at Khayyaban tavern, The Skeleton's Mug, or in Uziz from Maryata bint Daris at The Lofty Spire.

You'll read that the Bey of Xarabydun, Fazyad ibn Raymar, has put forth a Call for Adventurers who wander the A'mun desert. He's seeking heroes willing to rid the sewers beneath the town of vermin.

Call for Adventurers!
To all who wander the empty beauty of the great A'mun, I send greetings.

The young town of Xarabydun seeks those of the 25th level or below to cleanse the vermin from its lower levels. Those who can bring back trophies from these creatures will be well rewarded from the town's coffers.

Interested parties should travel to the town's entrance portal at 16.2E by 41.9S, in the wastes between the towns of Al-Arqas and Khayyaban.

- Fazyad ibn Raymar, Bey of Xarabydun

To get to Xarabydun, take the Monument Sands settlement portal from Al-Arqas (33.6S, 13.2E). It will drop you at 37.9S, 16.0E. From there it's just a short run to the city's entrance portal at 41.9S, 16.2E. The town is restricted to levels 25 and under.

The entrance to the sewers is locked (resistance 82). To reach the doors, head to the lifestone area to the right of the entrance and head down the slope. Follow the hall past a few shops until you see the glow of green from the sewer gases coming up from below.

After you pick the lock to enter the Xarabydun Sewers, take a left at the first split, then left again. Make your next right, then keep to your left until you see a ledge overlooking a portal below. On this level you'll be fighting Grey, Russet and Brown Rats. You may also encounter an Ethereal Wisp.

Jump down into the pit -- pay no mind to the bloody corpse covered in flies -- and head through the portal (restricted to level 1-25) into the Uninhabited Area.

This Uninhabited Area actually has some occupants: lower level Banderlings (up to Captain - level 12) and Parfal Niffis!

At the first intersection (4-way), make a right and head up the ramp to the second level. Take the east corridor out of the room and make a left at the 3 way split. Make the next left into a room with a Shadow Sprite a Wood Golem and a locked door.

To find the key, take the north passage to a large room with a few Banderlings and a sarcophagus in the center. Be careful! It's trapped! Opening it will release a Ghost Wisp and a fireball. Take the west passage out of the room. You'll soon encounter everyone's favorite vermin: Mites! The Guard Post Key is found on a Mite Squire. You'll also encounter the Mite Warrior Princess. Kill her and loot the 40 Discus off her corpse (unusable until you turn them in to Xarabydun Trophy Collector).

Head back to the locked door and use the Guard Post Key to open it. Pick the cell door to access the chest containing a Forgotten Text. Hit the button inside to open a door in the Mite Princess's room which will give you access to the level below.

The last section is the Lightless Tunnels. It's inhabited almost entirely by Knaths. When you enter, you'll have three halls to choose from. Take the east passage and follow a few ramps downward. Navigate SW through the area until you reach another ramp heading down. Take one last ramp down from this room to reach the Crystal Nodule room. You'll encounter more Knaths and a Dark Wisp. The nodules spawn every few seconds and you may pick up as many as you wish. Stock up! Crystal Nodules may be dropped or given away, so you can easily store them for later use.

Note: the lowest level of the Lightless Tunnels has a portal to the Mid Direlands guarded by 2 Shadow Children and a Scrawed Grievver.

Before heading to the Aino Lunnan Shin, stop by to visit the Bey and hand him your 40 Discus. He will return one which you can use as a weapon. (If you prefer to sell all 40, skip this part! ;-) Turn in any rat tails you may have acquired for additional rewards.

Aino Lunnan Shin, the Gem Crafter, can be found inside a tent just outside Xarabydun at 41.7S, 16.1E. Hand her a Nodule to receive a Gem of Impulse.

Aino Lunnan-Shin tells you, "Greetings." You give Aino Lunnan-Shin Crystal Nodule.
Aino's eyes light up at the sight of the geode.
Aino Lunnan-Shin tells you, "Ah. A precious thing indeed."
She produces a few jeweler's tools and reworks the stone, chanting obscure spells to herself as she works. Soon, she hands back a fine gem.
Aino Lunnan-Shin gives you Gem of Impulse.

The Gem of Impulse adds 100 points to your max mana for a duration of 3 hours; however, you may only craft one per week. After turning in the crystal nodule, the Gem of Impulse becomes no-drop, no-give.

For more information on the history and lore of the "Laerauinth" head to Cragstone to have your Forgotten Text translated.

You give Bretself the Translator Forgotten Text.
Bretself the Translator tells you, "Most interesting. It appears that the town of Xarabaydun holds a treasure I would not have suspected."
Bretself the Translator gives you Standing Orders.

Text: Standing Orders