In the midst of your assault on the Temple of Deep Chaos, your exhausting battle with the bulk of the cultist forces meant you needed a rest.  You retreated to the underground tower and sealed the doors.  

After resting, you headed north, and found empty chambers that must have housed the  rat brute guards you already defeated.   You also found the water source for the temple.

Further on, a mysterious room awaited.  A temple?  Offering chamber?  Gathering area?  You weren’t certain.  Chaos symbols adorned the walls and a large stone statute loomed in the center.  When Raelen touched the structure, its top slid back and some gruesome black beast emerged.  The beast paused a free moments before attacking; the blows from its morphing tentacles seems to physically destabilize whatever it hit, but it wasn’t able to do that to any in the party.  The battle was cut short and the beast defeated by a deadly accurate shot from Ebrahim and his recently acquired blazing bowstring.

With the stone structure re-closed, you decided not to tempt fate further and moved on.  You found the quarters of the medusa, and although hampered by a trap at its entrance, you were able to scour it for clues and come away with quite a bit of treasure.   You learned she was a member of the Pactlords of the Quaan, sent to infiltrate the cult and learn of a “machine” they were building, and something called the “final ritual”, but it was unclear if these were the same thing, or how they might be connected.

Further on, you found more buildings buried long ago.  Within one, a goat headed chaos demon (which you recall from the chaos texts was called a Rhodintor) served as a guardian.  He was a clever opponent and used cover to his advantage, but in the end he was no match for the four of you.

A long hall lead to the center of the temple.  Along the way the combined skills of Ebrahim and Phen were able to avoid a deadly poison gas trap.  The hallway ended at a bizarre chamber at the heart of the temple.

The walls were covered in reflective crystals, and the chamber itself was some eighty feet tall, with the floor fifty feet below.  In the center floated a stone island, an altar upon it, and chained prisoners suspended from below.  At the altar stood a dark-skinned cult priestess, Illadras, her body aflame with some chaositech mutation.  With her was a cult guard.  Her name and description matched a cultist that Carric had been searching for - one that had taken the runebearer boy Jol.

Carric, keen for revenge, fired Eldritch Blasts at Illadras, but any blast that missed her was reflected back at Carric by the crystalline walls.  In response Illadras drank a potion and took to the air.  Raelen used Misty Step to appear on the floating platform and began attacking the cult guard, while Phen and Ebrahim used ranged attacks from outside.

Suddenly a Wall of Fire appeared directly in the doorway, splitting the party.  Only by passing through the flames could you enter the room.  Phen made his way through the flames, then cleverly used a potion of levitation to lift himself out of them and float over the center of the room, and Carric did the same.  Ebrahim used every bit of his athletics to jump across the chasm.  

The cult guard soon fell, but a quasit familiar you had seen earlier reappeared suddenly and attacked Raelen; his blade quickly cut it in two.  Illadras then cast a Fireball down among you, and retreated under the floating platform.  Using his levitation, Phen followed her and cast a Hold Person spell, which worked - she was frozen in mid air.   Now an easy target, the party rained arrows and spells on her and she was soon dead, her body falling to the floor far below.

Carric quickly began releasing the prisoners.  Three were still alive but in terrible shape.  You healed them as best you could, and escorted them outside the chamber to wait.  While you debated whether to press on or retreat to the city, Phen went down to Illadras’ body where he found a magic ring.  He also heard a small group of cultists in hidden chambers below - the smell of smoke told you they were burning things.

Eventually, you decided to confront these cultists in disguise.  You found them burning documents and papers, and after persuading them to stop, interrogated them for a bit before killing them.   You learned the machine they were building was called the “Mrathrach Machine”, Mrathrach being the name of a game of chance played at one of the local gaming halls.  From examining some not-yet-destroyed papers, you garnered the name "Luth" as someone important to the cult.

With the temple fully explored, you escorted the survivors to the surface, and took the next several weeks to recover and plan your next move. . .