The short and sweet version is that after returning from the Sahuagin floatilla, they arrived back to town, sold their swag and were trying to solve any necromantic questions. They found out that the lord of the keep, Lord Blackstone, is gone and there are no guards posted anymore. They uncovered the necromancy guild (Neo-Prophetus) has a dungeon beneath the town, that the tower’s lake is full of corpses, and that the animals in the area are very distressed.
The party partied with the crew of the Invidious and went to bed.
The next day they wake up to the Spartes and Phoenix Elf vessels coming in to claim the isles back (based on the history of Nassau). They show up and offer pardons to all the captains. Two take them (Sid Seville & Yuki Scorchleaf, Jonathon Brisbane and the mage captain of the Arcing Corsairs, Sakura Manaflare say no.
The Spartes naval commander Doran Morphis, takes 10 knights and the party up to the keep to investigate. (Why isn’t the lord of the town showing up to argue against this?). They find out the necromancers have taken over the keep and after destroying some skeletons, the raging barbarian, Tazar Stoneblood, busts through a door (not planned for) and interrupted a summoning of a Bone Golem (Stone Golem weak to bludgeoning) and they killed it along with 4 cultists. They just leveled up to level 5 and will have to board up the castle and hold the line as the necromancy guild claims the rest of the city.