Overview: In episode 6, Battlefield Detectives: Massacre at Waterloo asks - was there more to Napoleon's defeat than the tactics and fighting prowess of the Allies? Waterloo has always been seen as a tactical victory for the Duke of Wellington, his small but highly trained Allied army outfighting the veteran soldiers of Napoleon's Grand Army. Now the latest scientific techniques are shedding crucial light on Napoleon's campaign. And a dramatic archaeological discovery is helping answer the central question: what went wrong for Napoleon at Waterloo? The program uncovers why, for the first and only time in their history, Napoleon's Imperial Guard broke and fled from the battlefield.