King Dugan's decision to let his guards eat lunch in the dungeon has had consequences. Crumbs accumulated, and with them came cockroaches—followed by goblins, serpents, evil eyes, and a whole taxonomy of things that should not be living in a royal dungeon. Beethro Budkin, dungeon exterminator and a man who has seen far worse, is summoned to the castle, given a brisk briefing by Dugan, and then locked inside with nothing but his Really Big Sword. His task: clear every room so that Dugan's prisoners can once again receive their torture in hygienic conditions.