A dwarf mining camp in the foothills of the mountains has uncovered an ancient temple/burial site while digging - with loot! However the expedition to recover the treasure is found slaughtered and the treasure is missing. Players investigate and discover a troll has entered the remote tunnels of the mine through its own cave system, and stumbled upon the miners, killing them and even eating the treasure.
Maybe the players hunt down the troll, delving into the caverns from the bottom of the mine, and face off against the mighty troll in its lair?
Perhaps the troll can be killed and a certain amount of treasure recovered from its belly? Maybe depending on how long it takes the party to kill the troll, the treasure dissolves more in the stomach!
The evidence of a dead troll slayer might be found? more clues to another adventure? Maybe the tunnels lead further into adventure?