 Documentary series in 4 parts in which  Henry Lincoln  (qv), co-author of "The Holy Blood and the Holy Grail", explains the original background to the  Holy Bloodline  hypothesis. Episode 1 "The Lost Treasure" begins on the Danish island Bornholm with the intriguing Templar churches. Lincoln then travels to the Languedoc to examine the history and influence of the Knights Templar, and to Rennes-le-Château, where the priest Bérenger Saunière supposedly discovered the now famous parchments. Episode 2 "Guardians of the Grail" explores the possible nature of the secret which led to Saunière s mysterious wealth. The clues point to connections with alchemy, cabalism, the Templars and the beliefs of the Cathars. Episode 3 "Only for the Initiated" explores links to the Templars, the Cathars and the Merovingian bloodline which hint a controversial interpretation of the nature of the  Holy Grail . Why is that shadowy organization, the Priory of Sion, so strongly linked to this story? In episode 4 "Exploration of the Invisible" Lincoln reveals the most astonishing discovery about Rennes-le-Château which again returns us to the churches of Bornholm.