The ruins of a dreamlike Polish palace hide an astonishingly dark history that's shrouded in mystery to this day; experts investigate and uncover an ornate gothic structure that concealed a nightmare of Nazi experimentation. Stories: 1) Bethlehem Steel Plant, Bethlehem, Pennsylvania; 2) Lindisfarne Priory, Holy Island, England; 3) Mokrzyszów Palace, Poland; 4) Lifta, Israel