Two rival factions are separated by the Dragon Bridge, the old bones of a dragon draped across a chasm.
This would be no more than a curiosity except that these bones are magical, and spellcasters occasionally chip away at the skeleton for bones of power. This is obviously destabilizing the bridge.
At any given time, there may be members of the rival factions taking pot-shots at each other or attacking spellcasters who are attempting to harvest the dragon's bones.
Worse, some have noticed kobolds in the tunnels near the bridge. Might they have a plan for the dragon's bones?
- A faction sends you to stop someone from chipping away at the bridge.
- The PCs are sent to the bridge to chip away a piece of it. A faction notices and attacks.
- A faction has a spell that can teleport the bridge away entirely. You have to protect a spellcaster while they perform the ritual while under attack from a rival faction.
- The PCs are sent to investigate the kobolds. They actually serve Keolarth, another dragon deeper in the caverns who has directed them to prepare the skeleton by placing various artifacts nearby. When that is complete, Keolarth can perform a ritual to turn itself into a dracolich. This can be communicated by the kobolds themselves if the PCs capture any, or by a captive.