A few days after Hemlock left town the adventurers new friend Ameiko was found missing by her assistant. Ameiko's brother Tsuto had left her a letter asking to meet at the Glassworks. Filled with concern for Ameiko's safety the adventurers made way to the Kaijitsu Glassworks to investigate.

The adventurers arrived to find the Glassworks locked and deserted, but strangely there was smoke coming from the chimneys. They attempted to break in quietly but lacked the skills, eventually they procured the help of a local locksmith Volioker Briskalberd, who was suspicious of the adventurers at first but conceded that there was something suspicious going on inside the glassworks. One inside the shriek of gleeful goblins could be easily heard coming from the main glassworking room. The adventurers entered to find a group of goblins defiling the bodies of all of Sandpoints glassworkers: slicing some up to put in the furnace and pouring molten glass onto others. The adventurers skillfully dispatched these creatures with a well timed sleep spell. Once the battle was over the body of Lonjiku Kaijitsu was found propped up in a chair in the central alcove, encased in thick, runny sheets of hardened glass.

The adventurers began to explore the rest of the glassworks, and came across another goblin, who screamed in fear and ran down to the basement where Tsuto and another goblin were waiting. After a short fight Tsuto quickly realised he was outmatched and began to run down a recently uncovered smugglers tunnel but the adventurers relentless persuit forced him to fight. He was quickly subdued and bound before being given to the town watch and taken to the garrison.

The adventurers found a diary in Tsuto's makeshift study which detailed that he is working with the Thistletop goblins. It reveiled that the real purpose of the initial raid was to steal Father Tobyn's casket but the same won't be true for what Tsuto refers to as the "real raid". Tsuto then goes on to detail a plan of attack for a future raid on Sandpoint. He talks of a quasit and other creatures below the glassworks. He mentions the goblin heroes Ripnugget and Bruthazmus and a creature called "Malfeshnekor" that lives in some "lower chambers". Tsuto then goes on to talk about his lover who is going through some sort of infernal transformation, fueled by worship to Lamashtu, the mother of beasts.

The adventurers rescued Ameiko and she was distraught by her brother's treachery! Tsuto revealed to her that he was working with a group of mercenaries led by a woman named Nualia, the Aasimar daughter of the old priest Ezakien Tobyn. Tsuto told Ameiko not to be in town when his plans came to fruition and offered her a chance to join his mercenary group on Thistletop. When she refused and slapped her brother he unleashed his goblins on her and left her locked in a room in the basement of the glassworks. Ameiko was eager to warn her father of her brothers plans so the adventurers broke the news to her, causing her to break down in tears.

After escorting Ameiko back to town the adventurers decided to explore the tunnels below the glassworks. The old smugglers tunnel led to a cave by the beach that had signs of recent occupation by goblins. The cave had another tunnel leading off it towards an ancient ruin, presumably undisturbed for thousands of years until the smugglers accidently tunneled into it. The adventurers found that the residents were grotesque and hostile humanoid creatures with clawed hands and monstrous jaws.

They began the exploration of the ruins and found an ancient prison and torture chamber, as well as an ancient study. Avoiding stairways, for fear of progressing the plot prematurely, the adventurers came upon an ancient shrine to Lamashtu and an immense underground cathedral. At the top of a stone stairway sat a strange triangular pool of churning, bubbling water that reminded the adventurers of lava. The only resident of this room was a mad quasit who flew into a rage and attacked the adventurers, but not before spilling some of her own blood into the pool, causing it to form another of the monstrous humanoid creatures that inhabit the ancient ruins. After this had happened, the pool noticably dimmed, as if it had lost power. The adventurers found this tiny demon a difficult adversary to pin down, but a heroic leap from Seoni allowed them to grapple her to the ground and club her to death.

After vanquishing the strange guardian, the adventurers managed to deactivate the strange glowing triangular pool within the ruins under Sandpoint by exhausting it's ability to spawn creatures. After this event they continued their exploration of the old ruins, facing a strange demonic winged skull known as a Varghoul and finding a spiral staircase up to the surface blocked by a cave in. At the other end, the adventurers found a crazed mutated goblin guarding a room full of imprisoned zombies and a strange spherical chamber with exotic magical properties. Mirroring the spiral staircase upwards, a staircase leading into the earth was also blocked by rubble.