The characters of my players were spent after clearing the upper level. This was actually their second attempt at the place.
Unfortunately, they had let a goblin escape, and he made his way downstairs to get the longshanks down there (including a Tsuto who had escaped the Glassworks). They hid in a rope trick to rest up.
In my case, Nualia abandoned Thistletop to go to the Mosswood and try to recruit more goblins. Convincing the chief to split the tribe and send some of the troublemakers to Thistletop to occupy the preferred lair seemed like a good plan to her. She left her hounds as guards, and headed out.
Orik, Tsuto, Bruthazmus, and Lyrie were sent to ambush the party when they headed back to Thistletop... a faster-moving set of goblin spies kept watch for the PCs coming back. THat led to Orik and Lyrie being captured, and turned over to Magnimar for judgment.
I had a similar experience to Urath.
then advanced carefully over the stone arch (which I had at the last minute replaced the rope bridge with, as I hadn't had time to build that danged rope bridge)...
and proceeded to gank the guards, then sneak into the heart of Ripnugget's domain,...
where they barely managed to come out on top, with one player death and everyone else at the raw edge.
On a subsequent session, (but immediately afterwards in game time, thanks to a generous supply of healing potions) they penetrated into the depths, convinced that Nualia would soon fall.
- the barbarian leapt into the sea from an open ledge, and swam to safety
- the fighter had a close call with the tentamort, then managed to climb out to safety
- the wizard, through raw luck, ran back exactly the way they came, and only had to trip over a few goblin corpses on his way to fresh air and freedom.
Now i have a question i've been pondering. What does Nualia do when she realizes all the goblins are gone? She still has her other allies, but it's clear that someone is bound to return to get them.
Here's what happened in my campaign:
My logic was that Nulia was clever enough to "run to fight another day", knowing she could return to Thistletop once the heat had died down. She never made it that far, though I left the players thinking
My interpretation of Nualia...
Nualia is a vengeance-obsessed lunatic who is a cleric (fanatical follower) of a demonic Goddess of Depravity. If it can't be done in anger and with perversion, it's not worth doing. Crisp, objective, rational thought is not what she does. Lamashtu gave her a holy quest to free Malfeshnekor and burn Sandpoint to the ground as a sacrifice to complete her transformation to demon. She is well-suited to this mission because she loathes the people of Sandpoint with every fiber of her being. She's not leaving Thistletop under almost any circumstances; certainly at a minimum, everything else in the place will need to be dead before she retreats.
What happened in my campaign when events went similarly to the OP...
The pc's had cleared the above ground portion of Thistletop (including the thistle maze) and retreated. When they returned, they found the survivors (Nualia, Lyrie, Orik, 3 yeth hounds, a wounded Bruthazmus and Ripnugget) in defensive positions in and just outside the Temple. What followed was an immense battle - Orik surrendered at 1 hp, the pc dwarven fighter went through his hit points 3 times (with all the healing) and Nualia ended up cornered in the Prison (D9.) The pc's, who had some sympathy for her based on research they'd done prior to arriving at Thistletop, offered her a chance to surrender. She channeled negative energy at them in a "for hate's sake, I spit my last breath at thee" sense. Surrender declined, death ensued.