If you played the Alton mod for Fallout 3, chances are you found a Mysterious Book in Houck Residence (the southeast area of the map). If you try to pick the book, you'll hear an unlocking sound, but nothing happens. Upon some search in the comment section of the mod page (using the forum), I found that the content related to the book was cut before release. Ignore that book, and don't spend 15 minutes trying to figure things out (like I did).
