The black dragon Keolarth lives in a fissure deep within the earth, protected by a huge tribe of kobolds. Keolarth is famously difficult to kill because despite several entrances to the the fissure, it runs for what seems to be miles, affording Keolarth many places to run if a battle goes against him.
The center of the fissure opens out noticeably, and the nearby wall juts out into a promontory where Keolarth prefers to hold court with his fawning kobold minions. Many treasures are packed into odd crevices in the fissure walls here, so that everywhere Keolarth looks he can see proof of his past conquests.
A river of water sits a few dozen feet below the promontory and runs the length of the fissure, though it moves so sluggishly that scum grows on its surface. At any given time, there are usually a few humanoid bodies laying in the river, ripening to just the point of putrefaction preferred for Keolarth’s palate.
- Marina, a valiant heroine from another underground faction, has been captured by Keolarth's kobolds. The faction hopes that she's still alive and sends the PCs to rescue her. If they're lucky, they arrive in time to find her bargaining important information for her life.
- The PCs are tracking the kobolds back from the dragon bridge and discover the fissure. They must kill enough kobolds to make it unlikely that they'll have enough members to re-attack the dragon bridge any time soon.