i've designed a dungeon for 3rd level pc's. it's an abandoned dwarven mine that's been flooded. they need to activate the ancient (but still functional) dwarven pumps to drain the mine to get to the lower levels. i can't think of a good power source for the pump. i need it to be something dwarvish, and portable. something that's not going to thrwo the game. i don't know, i should be able to think of someting but i'm at an impasse. i can't think of anything i like.
some unknown ore? a wand of lighting? magic coins?
i don't know.