Geiesburg and Iserlohn fire at each other, causing little damage to the fortresses. After that, Schenkopp and the Rosen Ritter repel a boarding party. Kempf then decide to use the firepower of Geiesburg and the Müller Fleet to make a breach in Iserlohn's outer wall. The operation succeeds, but the Imperial forces can't get through because Admiral Merkatz launches the Iserlohn Fleet and drive off the Müller Fleet. Meanwhile, Yang is on his way back with some reinforcement. April, 15, 798 S.C. / 489 I.C.: in spite of the numerical advantage of the Imperial fleet, the situation is deadlocked. However, Müller learns from a dying prisoner of war that Yang is not in Iserlohn.