Head towards the well West of Marshe.
Dagran, Syrenne, Yurick and Lowell will join Zael in this optional chapter to recover a book that Horace lost. This book will allow the party to uncurse weapons once returned to Horace.
From the starting point, turn around and enter the narrow passage to find a Chest and possibly a rare item.
Continue on until the party reaches a save point and dead end. Examine the rock wall, and Zael will kick it open.
The party will find themselves in a large underground ruin. Press onward to find a lizard archer, in First Person mode, seek him. Dagran will chase the lizard and then get surrounded. Kill all the lizards and their reinforcements.
Once that's been done, search the area for a nearby treasure chest, then move on through the gate where the lizard reinforcements came from.
Chase down any lizards, but beware of the archers with Burst arrows. Seek out all the lizards and kill them. This new area has one chest as well. Instead of heading through the door the party is waiting at, go to the farther door at the right and go through the narrow pathway, there are two chests there. Continue onward to the save point.
Go to the next area up the stairs and open the gate. There are three pathways, each with lizards guarding chests. Examine the giant statue to get some details about it.
Clear out the lizard groups in any order. Open the chests in each area to get an Ivory Fang charm.
One of the groups will drop the Oni katana.
Once all three fangs have been collected, examine the statue of the lizard near the stairs. Zael will stick the fangs into the statue and reveal a hidden stairway. Head down the stairs.
Syrenne will comment about the ridiculous amount of treasure hidden in the area, however you will not be able to access it yet. Continue down the hall and the party will note there are two Giant Lizardmen there. Shoot them through the cell door to lure them over to the party. After defeating both, continue on to the room they were guarding. There is a Summon Circle in this room if leveling is desired.
Open the door to the next area and move on. Save if needed, then go through the next door to a large room with two statues and pillars in it. Be prepared for a cut-scene and then a boss fight.
Queen of Abyss
This thing is the Lizard folk's 'god'. It is also really huge. Do not let eat/swallow up the other party members. When it does however try to swallow Zael, follow the on-screen commands to avoid being eaten, and continue to attack it.
To have it 'eat' Zael, use Gathering to draw its attention and lure it away from the other party members, as she can one hit kill them. In order to deal heavy damage to the Queen, lure her to one of the orange cannon shells, and when she's about to eat Zael, roll away. She will instead throw the cannon shell up and swallow that instead, causing massive indigestion (and damage)!
If the Queen has one of the party members, pick up a cannon shell and throw it at her mouth to save that person.
Defeating Queen of Abyss will earn the party Flame Lizard (Cursed).
Head up the altar where the lizards were dancing to find Horace's book and get out of here through the doorway.
There will be a rather amusing scene involving counting how many stairs the party has to climb as they try to leave.
Zael can now go to Horace's store to get any equipment he finds uncursed if needed. Uncursing is free, however it does require one Light of the Outsider for each item that needs to be uncursed.