Base of Operations (3.0) (d20)
A group of vile humanoids has taken over an old¸ ruined keep within a day's walk of the nearest town. Local leaders greet this news with alarm¸ for they don't wish to see a stronghold for evil humanoids so close to their settlement. So they offer a deal to your group of adventurers: Root out the humanoids and you can have the keep as your own base of operations.
Base of Operations¸ a short adventure intended for four 5th-level characters¸ is a site-based scenario designed to be either very brief (one or two sessions) or part of an ongoing campaign.
Player characters have the opportunity to save a town from a horrible fate¸ rid the world of a vile necromancer¸ and find a little wealth in the meantime. Or¸ if the DM wishes¸ the adventure allows for player characters to set themselves up in their own "base of operations" and become permanent members of a community.