She was called because she is the best cryptologist and archaeologist in Northern Germany. But Marlis Lindenkamp doesn't know how to deal with her new colleague Sven Klempow. She has to decipher two mystical secrets in Wismar. The history of the finds goes back to the Middle Ages, to the years of plague and pirates, to the time of the Reformation and to Wismar's Swedish period. Marlis also has a very personal secret on her mind. Wismar comes first in everything, because the images of the eras, Nosferatu's demons and Marlis' ideas flow from the bricks...