Hindenburg has been appointed the commander of all German forces in the east, with Ludendorff his chief of staff. They get wind that the Russians are preparing to launch an attack over the German border into Silesia. To forestall this, the Germans launch their own offensive into Poland. As well as preventing the enemy’s Siliesian offensive, the Germans hope to drive the Russians out of Poland once and for all.
Mackensen commands the troops spearheading the German thrust. He finds himself up against Russian troops commanded by Rennenkampf, the loser of the Battle of the Masurian Lakes. Perhaps thanks to the amazing hat of their leader, the Germans are able to smash through the Russian forces, taking many prisoners. The Russians are routed and begin a retreat to the Polish city of Łódź.