Goblin Den

Having met with a dwarf barbarian during an encounter with a swarm of goblins, the party is able to relax and enjoy an uninterrupted long rest with Karl Wyrmkill in his lodging. His lodging turns out to be a series of three caverns loosely connected much further up the ridge from the river than you encountered the goblins. There is a small cave entrance leading to a large cavern deeper into the hillside down a long passage. There are several small passages leading away from this cavern. Karl insists that most lead to dead ends, while some have access to a spring. There is a third cavern a few hundred yards away, well concealed from any approach to the main entrance, that is connected to the larger cavern as well. Karl refers to this bolt hole as his back door.
The night passes uneventfully within the large chamber. In the morning, he will offer to escort you overland around a waterfall that lies three hours upriver. He assures you that it is a gentle enough route to allow you to carry your boat with you, and insists that it is better than taking the usual portage around the waterfall. According to Karl, there is a strong bandit presence in that area of the river, and they have many spies informing them of possible targets. They like to stay out of sight, and wait for travelers to make their ascent over the portage, then ambush them on the way back down to the river where they can take them by surprise from caves on the downslope. They kill and ransack as much as possible, then run anything extra over the waterfall in the boats to smash them on the rocks below.
Karl's been watching them, and working out a way to deal with them, but feels the first thing to address are the goblin spies working for them. He asks for your help in attacking their den. The goblins you met at the river were spies that would have betrayed your presence to the bandits upstream, allowing you to fall victim to them during the portage. He claims they all are part of a den of goblins that live two miles up the gorge from where you left the river. He knows a back way into their hideout, and thinks that together you can overwhelm them and destroy their chief. Without a leader, they will scatter into the hills, giving an opening for dealing with the bandits unawares.

On the map accompanying, the main entrance leads into chamber 1, with secondary exits near chambers 5 and 8. Karl leads you to the entrance leading to chamber 10.
Rm 1-2 goblins, R2-Bugbear chief and 2 bugbears, R3-goblin boss and 4 goblins, R4-3 goblins, R5-8 giant rats, R6-2 goblins, R7-1 bugbear, R8-3 goblins and 1 rat swarm.
Chambers 7 and 9 are separated by a large, murky pool filled by greasy water dripping from the ceiling. There are three pools in chamber 9, cutting this section of the den off from the main part. This is how Karl hopes to defeat the goblins, by sneaking up on them from deep within their own den. The rooms are not unguarded. Room 11 has a swarm of bats, with guano covering the floor (DC17 Survival check to equate the guano with a bat cave). Room 10 has 3 giant spiders. Room 9 is the reason the goblins don't fear any approach from that direction. There is a roper in the chamber, along with three piercers, blending in with the stalactites and stalagmites in the cavern. The party can deal with the bats, spiders and roper without arousing any real interest from the goblins since they expect the monsters in room 9 to deal with intruders on a routine basis. It will amuse the goblins. However, the bugbear in room 7 will notice their presence, and unless dealt with quickly following the defeat of the other monsters, will be able to raise an alarm.