Book excerpt: A riveting true story of murder and detection in 15th-century Paris, by one of the most brilliant medievalists of his generation. On a chilly November night in 1407, Louis of Orleans was murdered by a band of masked men. The crime stunned and paralyzed France since Louis had often ruled in place of his brother King Charles, who had gone mad. As panic seized Paris, an investigation began. In charge was the Provost of Paris, Guillaume de Tignonville, the city's chief law enforcement officer -- and one of history's first detectives. As de Tignonville began to investigate, he realized that his hunt for the truth was much more dangerous than he ever could have imagined. A rich portrait of a distant world, Blood Royal is a gripping story of conspiracy, crime and an increasingly desperate hunt for the truth. And in Guillaume de Tignonville, we have an unforgettable detective for the ages, a classic gumshoe for a cobblestoned era.