Dylan Hartwell, of the cool blog Digital Orc, has a new free adventure module out called The Cell Within. It's a nice, short, but very evocative module. It'll give you a good night or two of play. You can check it out here.
Full Disclosure: I'm one of the editors of the module, and Dylan's one of the artists contributing to Flying Swordsmen RPG. So of course I want you all to go check out his stuff! Seriously, though, it's a cool module. Serial killers and pig-men. What's not to like?