A cluster of military defensive structures among a quaint holiday village lies deserted on a San Francisco Bay island; experts investigate and uncover a mysterious Civil War outpost on Angel Island that conceals a dark and hellish history.

An opulent chateau perched in the middle of a lake, the Château de la Mothe-Chandeniers, now stands dilapidated in the Loire Valley of France. Experts investigate and uncover the remains of a festering palace whose owner was labeled a traitor by France's most notorious king.