Rennes-le-Château is a small village in the French Pyrenees where, in the 1890s, a poor parish priest named Bérenger Sauniere found coded parchments hidden in his church, traveled to Paris to meet occult figures and ecclesiastical authorities, and returned to spend money he had no visible way of earning. Presenter Henry Lincoln, working with co-researcher Michael Baigent, lays out the evidence he thinks explains it: the mountain tops around the village, when plotted on a map, mark out a precise pentagram, and churches, chateaux, and landmarks for miles around fall into an interlocking pattern of circles and geometric stars. Produced by Roy Davies for the BBC's Chronicle series, the film is the third in a run of documentaries Lincoln made on the subject, following 1972's The Lost Treasure of Jerusalem, and its research fed directly into the bestseller Holy Blood, Holy Grail, which Lincoln and Baigent later wrote with Richard Leigh. The geometry is presented as measurable fact; whether it explains anything is left for the viewer.