Rouen is one of the great cities of medieval France. Situated on the banks of the River Seine - a vital trade route for both European and Scandinavian countries - it is the capital of Normandy. Its population comprises some 25,000 souls, making it one of the largest cities in north-western Europe; and on market days this number swells dramatically. For visitors unaccustomed to the noise, smells and vivacity of metropolitan life, Rouen is an awesome and even terrifying sight. Of course hidden amongst the swirl of city life, Rouen conceals a number of dark secrets. There are things lurking unseen amongst the innocent citizenry; things that can change their shape or glamour those around them so they may pass for human, occultists that seek to increase their knowledge and swell their ranks. These beings have agendas of their own and, if not stopped, will seek to control and guide this proud city towards their own, nefarious ends. This sourcebook will take you through the streets of 12th Century Rouen, to the darkest areas of the city where there are few friends for Guardian Priests and far too many enemies.