We started mid adventure, in the thieve’s guild under the Brackish Keg. Present were: Jeff’s druid, Doug’s alchemist, Roy’s witch, and Hobie’s war priest (Todd’s healer was not with us, but did not start into the guild stronghold last time. Eric’s barbarian started with us last session, but was hand-waved not to be there this week).
In the first level, the party managed to bypass the gates in the prisoner’s area and get into the fight with the barkeep, the cultist and a few guild members. The cultist moved down the stairs to the second level, and we killed the barkeep and remaining thieves on this level.
The witch went invisibly down into the lower level first and saw that more thieves and a gnome had set up a barricade of tables and were ready to fire crossbows at anyone coming down the stairs. The druid in bear-shape came down next, but all of the crossbow shots missed. Hobie and Doug followed. The fight raged in that room for a while.
In the fight, the cultist showed up again, this time in his true form as a serpent person. The gnome (later identified as Trask, second in the guild to Finn), cast mostly defensive spells and attacked occasionally when he had a flank with the thieves. The war priest was taken out of the fight for a few rounds when he was dominated by the serpent cultist.
As the fight wound down, the serpent cultist was killed, Trask escaped by Dimension dooring out, and all but one of the thieves was killed. The last one was keep alive so he could be questioned.
From him, you found out that about 1/2 of the dungeon was used as a training area for the thieves (Hobie briefly interacted with a construct before withdrawing). The party did not explore that area of the hideout.
In another section, there were underground connections to the sewers under Freeport. As soon as Doug noticed something large under the water, the party backed out of the area. The one surviving thief said that the serpent cultists were bringing in the prisoners to the guild to then be sent out with what the thief called a horrible spider thing. The guild is apparently acting as a waypoint/middleman for the slave trade between the cultists and the other group.
All of the prisoners were set free, going back out through the upstairs bar area. The party did not explore further into the guild headquarters nor the sewers.