1688, The Netherlands. Master Mercurius has just settled back into his life as a lecturer at the University of Leiden when he is once again summoned by the Stadhouder, William of Orange. A message from William is never good news, but he is not a man you can say no to. So Mercurius finds himself once again uprooted and at the center of dangerous political plot. William has decided it is time to expand his empire and launch an attack on his nemesis, the French King Louis XIV. And to keep the element of surprise on his side he has decided to march through Germany. To keep the Germans from blocking him, William has decided to make use of Moers, the German stronghold he inherited which he is allowed to occupy and arm. But he needs someone in control there. And that is how Mercurius finds himself as the newly appointed Governor of Moers. William has promised that Mercurius will be executed if the secret plan is discovered, so can the Master keep it under wraps? Or will he be facing the hangman's noose?