Thirty naval officers to sail the seven seas, salty sea dogs all. Some are explorers, some are traders, and others are out on missons of conquest.
Seven naval commanders with the power of life and death over their men when at sea. Theirs is a lonely post, as they are responsible for their men and the ship that they sail in. Some are legally appointed, others are mutineers with not much to lose.
The Admiral of the Fleet, an exemplary commander, peerless in skill, ruthless in execution.
Also happens to be a 14 year old girl.
The Yugzhee, or "hedgehog-people", guard a great, secret treasure inside their giant burrowed lair. The mysterious Wall of Keys, a 12'x10', foot-thick, cold-iron, "wall", upon which, on iron hooks, hang 100 ornate iron keys of all shapes and sizes. Each key opens some heretofore un-openable barrier, door, or gate, in the particular game world of choice.
The PCs have come upon a great boon, except for the fact that the keys cease to function properly if separated from the iron wall for more than a few minutes. Higher level characters will be able to figure out how to take the wall "with them" via magic. Lower level characters will have to get creative.