What's The NPC Want?
1. To get out of this fucking dungeon.
2. Revenge on a major monster in the dungeon. Random location. Roll a d12--whichever is furthest away near that o'clock
3. A fantastic treasure hoard they believe to be located...If your rooms aren't numbered so as to be rollable on a dsomething, roll a d100 and a d100 --it's somewhere around that location, treating the map as a cartesian grid.
4. The PC with the highest Cha.
5. A magic item they believe to be in the dungeon. This can either be one you already put in there or--if there aren't any--a regular item that you have in the dungeon that this loser thinks is magical.
6, To desecrate one of the altars in the dungeon.
7. To stir up dissent within one of the occupying factions (the goblins, the cultists, whatever) in the dungeon
8. To locate the rest of his her party.
9. To invent preposterous but plausible objectives to keep the PCs busy while s/he bumps them off one by one.
10. To slay and replace one of the heads of one of the factions in the dungeon.
Why Should The PCs Care?
1. NPC's an (average PC level + d4) wizard and if they don't help s/he'll kill them all.
2. NPC secretly or overtly controls a powerful faction in the dungeon.
3. NPC demonstrates extensive knowledge of much that is hidden--and will reveal more in exchange for aid.
4. NPC has a posse, a bad temper, and a map of the dungeon.
5. NPC is really hot.
6. NPC is on good terms with powerful creature in the dungeon and can get the PCs past it.
7. NPC has oracular powers or is a cleric with a few cure moderate woundses up his/her embroidered sleeves.
8. NPC is Sacred Fool of cleric's religion and cannot be harmed. Actual aiding is optional, but is recommended for ambitious holymen.
9. NPC is in a position to offer the PCs a sizable monetary reward once they are safely out of the dungeon.
10. NPC is like part faerie or leprechaun or something else enchanting and annoying so if the PCs don't help things may get a bit "whimsical".