First, peculiar discoveries in the 4,000-square-foot Baytown, Texas, home of Kristine and Bear Estrada include a 16-foot-deep Cold War bomb shelter, still stocked with supplies, in the backyard. Next, finding a red velvet rope, multiple 1950s phone lines and presidential mail make Denver, Colo., homeowners Nancy and Dave Osburn think something very important went on in their home. Then, after finding bloodstained wooden floors and both Confederate and Union bullets throughout their property, Linda and Curt Follmer discover that their 1834 cottage was used as a hospital during the Civil War. Finally, Sharon and Ken Avey's 1897 home in Independence, Calif., came complete with a strange peephole in the kitchen built to peek in on some unusual residents. They embark on a quest to find out who, or what, used to live in their home.