"Paris, Year of our Lord 1313. As the celebrations are in full swing in front of Notre-Dame Cathedral, Adam, a young ingenious goldsmith working on behalf of the King, mysteriously disappears... Who is so keen for him to vanish? What is his secret? What secret invention was he working on? Jacques, his brother, actress Rosemonde and circus-rider Pierre de Cinq-Ormes each set off in search of the truth behind his disappearance."