Major Schroeder was a German officer during World War II. He served in Yugoslavia and commanded a mixed group of German soldiers and Chetniks, working closely with Captain Drazak. When Keith Mallory, John Miller and Mike Barnsby's group arrived in Yugoslavia and were captured by Drazak, Mallory insisted they were defectors who had stolen a large supply of penicillin from an Allied base and hidden it somewhere in the wilderness. Schroeder didn't believe them, but was intrigued at the prospect of acquiring the highly valuable penicillin anyway, so he sent Cetnik soldier Maritza, his lover, with Mallory and Barnsby to dig up the penicillin.
He kept Miller, Reynolds and the others held prisoner in the dungeon, where two SS officers and a Gestapo agent arrived to question them. In the meantime, Maritza revealed herself to be a Partisan spy and not a Chetnik, killing the three Germans who Schroeder had sent to accompany her. She, Mallory and Barnsby then returned to Schroeder's headquarters to rescue their companions, forcing the unwitting Unterfeldwebel Bauer to take them to where they were being held. In the ensuing rescue, Bauer shot Reynolds, and when Barnsby killed Bauer in revenge, the Gestapo agent pulled a gun, and Lescovar shot him and the two SS officers.
Schroeder was taken prisoner, but as the group moved outside, encountering German troops, the Major was accidentally shot and killed by one of his own men. To escape, they propped Schroeder's dead body up in the backseat of his Kübelwagen and under cover of darkness drove safely past the sentries. They later dumped the vehicle, pushing it down a hill with the dead Schroeder still in the backseat.