The Quick Version since I have fallen behind.
After the battle of Farshore the leadership question of the colony needed to be settled. The Mayornenshi faction spread rumors connecting Lavinia to her her undead brother and a family curse. The PCs chose to stay out of the politics and Lord Manderlay won the election easily.
One of his first tasks was to clear the trade route back to the mainland and asked the PC to remove a Dragon Turtle that was known to live on the north end of the island. The PCs, spotting a cave while trying to lure the dragon out, went to investigate. They stumbled upon a settlement of diseased troglodytes who were dispatched easily. The troglodytes were dispatched with ease and two captives were found: a feeble minded human in rags and a healthy troglodyte. The human was restored and he said we was a missionary from Garund. He was spreading the word of Sarenrae and was attacked by strange men with animated skins on their back. Next thing he knew he was here.
The troglodyte was a member of the tribe but never received the blessing of their god (the disease). He began to suspect that something was off an was imprisoned when he spoke out. He told the PCs of the Shadow Pearls. The tribe were the middle men between the Lords of Dread below and the Crimson Fleet. Uzeye recommended the they travel down and speak with the Father who could tell them more.
Along the way The PCs did battle with a Roper and visited the Mongrel settlement of Bargas. There they were shown a petrified fish that was actually an Aboleth that had dried out and was in "Long Dreaming" a state of petrified hibernation. The was likely due to the Cerulean Curtain, a blue ghostly wall that forced sea water out of the area.
The PCs continued their trip down into the earth under the island. They finally reached the temple partially willed with slimy, scummy water and spoke with the Father. The ghostly troglodyte told them of the war of old - a conflict between the Olman civilization above and the Aboleth below. After many honorific sacrifices Tlaloc, the reptilian god of Rain, intervened and created the Tear of Tlaloc. This was dropped into the Aboleth city of Golismorga forcing the water out and putting most of the Aboleth into a state of hibernation.
After many years the aquatic race of Kopru moved in and tried to learn the Aboleth's secrets. An old temple in the city was dedicated to an Elder Evil. Tapping into the Black Blood of the Earth they managed to master a process of finishing Shadow Pearls - weapons of mass insanity and chaos. The Father suggested that if they wished to disrupt the process the should first destroy the artifact Tlalocs Tear which will cause the Kopru to panic as they rush to remove to finish off their ancient enemies the Aboleth leaving the temple relatively undefended.
As Tlaloc's Tear crumbled to dust, the earth began to rumble as the vast caverns under the city began to fill with water. The PCs rushed to the the temple and were assaulted by the Kopru Behemoths. One managed to Dominate Isis. Only a quick Hold Person by Trevain prevented Isis from killing most of the party until the controlling Kopru could be slain.
On the Workbench this Morning
1 day ago