They wielded a double-edged sword, combining military might and impressive financial power. The Pope himself couldn't escape their long shadow and the whispers about a fabulous secret treasure, which was said to include the Holy Grail and the Ark of the Covenant. So who - or what - brought down the mighty Knights Templar? This is the story of an organisation extinct for nearly seven centuries, but whose legacy still echoes through some of today's "secret societies."