The German Empire in the year 1200. In the wood brook ravine in the Black Forest the miller’s son Antonius finds a mysterious stranger who is injured and without orientation. He carries a valuable sword and a secretive wooden octahedron. Meanwhile, the events come thick and fast in Rome: The Vatican takes a precious relic out of the church in Santa Croce whose counterpart is said to be lost. Bruno von Sayn, an envoy of Otto von Brunswiek of the House of Welf, gets a mysterious message and everything points towards his former home – the far off Westerwald. Dark horsemen cause harm there and spread fear and terror. In the meantime, Hermann, the abbot, is looking for a place to build a new monastery with his twelve fellow believers. But what is the relic all about and which role does the secretive rose play in all of the events?