First, mysteries in the 1829 home of Jan Howell in Decatur, Ala., keep piling up. For example, a second-story door leads to the outside, but there is no exterior staircase. Next, Kewanee, Ill., residents Kathy and Bob Miller examine the past when they find medicine bottles, a medical diagram and an unusual fire extinguisher in their 1917 arts-and-crafts style home. Then, Amy and Jim Estep were thrilled when they found a hidden staircase behind a wall of their early 1900s American Foursquare in Cincinnati. Finally, when Judy and Frank Habjanetz bought their 1813 farmhouse in West Hickory, Penn., they had no idea that they would be inheriting practically everything the previous homeowners owned.