A long day coming to a close

In which Sam and Dean receive unexpected help from an apparently insane Librarian with a sword and his ladylove while hunting a bunch of ghosts. One-shot based on prompts made by a friend. Random hints for other shows. Features ridiculousness (not by the boys, naturally), a handkerchief with a monogram on it, a sextant, a ship and a goddess. Oh, and a clown's mask, obviously.