After being given a mysterious signet ring that belonged to her father, Aurore, a young blind woman, embarks on a quest to discover the truth about her grandfather Henri. According to the legend, he was to be the heir to Louis Braille's famous dot-matrix, which has gone missing for 180 years. Her quest leads her into a cloak-and-dagger fight for the matrix. After several mysterious attacks and successive deaths, Aurore finally learns the truth about the deaths of both her father and her ancestor Henri. Two destinies closely linked, as is her own, to that strange device: the matrix. Mixing historical facts with fictional drama, the two stories in this fast-paced thriller are cleverly intertwined.