The ancient fortress of Trifels was once the heart of Germany. Richard the Lionheart was held captive here. Here, according to legend, Emperor Frederick Barbarossa sleeps eternally in a dungeon. And here lies a terrible secret that can change the fate of all of Europe... The life of Agnes von Erfenstein, daughter of the governor of Trifels, changed in an instant. Just yesterday, a proud and freedom-loving girl was hunting in the surrounding forests and did not know grief. And today her father is dead, she herself is married to a stranger who has long sought to take possession of Trifels, and war is raging throughout the area... Agnes’ husband is obsessed with the dream of finding the untold riches of the German Kaisers in the dungeons of the fortress. But she herself feels that the secret that the ancient walls keep is connected with a completely different treasure, the true owner of which is she, Agnes, and no one else...