For the invasion of Poland in September 1939, his regiment was attached to the XIII Army Corps, a part of the 8th Army. Near Warsaw on 24 September, he was one of four men selected by his company commander, then SS-"Hauptsturmführer" Wilhelm Mohnke to negotiate the surrender of Polish troops during the Battle of Modlin. He was picked because of his ability, although very limited, to speak Polish. After the negotiations failed, the Germans headed back to their lines. When they were about 80 metres from the fort, firing began. Several rounds struck Misch, who fell down and lost consciousness. Some German soldiers carried him to an aid station. Later, he was transferred to two different hospitals. Thereafter, he spent six weeks at a convalescent home. For his actions, Misch was awarded the Iron Cross, Second Class. As Misch was the last living member of his Lower Silesian family, Mohnke recommended him for the "SS-Begleitkommando des Führers" (Führer Escort Command; FBK). This was made up of SS members, including men from the LSSAH, who were not serving on the front lines.