The Pilgrims Tale

Whilst in France researching his next book, an author stumbles on an ancient burial. This leads him to discover the answer to a mystery regarding a long lost and valuable religious relic. He sends tantalising clues to his daughter in London but then dies suddenly. The clues have to be followed, leading a group of friends across France on their trail. However they are not alone. Unscrupulous crooks are on the same trail. Can the amateurs keep ahead of the professionals?