In the southwest corner of Pennsylvania, beyond the picturesque scenes of the Monongahela River Valley, there are long-forgotten mysteries of scandal and murder. Amid the hardship of life on the frontier of Washington County in 1795, young Isabel Stewart was found dead and her killer never identified in the oldest unsolved murder in the region. La Mano Nera (the Black Hand) gangs from Calabria, Italy, extorted and slaughtered their way into the 1920s...