Wentzel Ahbe was a decorated U-Boat captain who'd survived countless depth-charge encounters during the Battle of the Atlantic. In March 1945, he took command of U-1324 for what would be his final mission: ferrying Lt. Col. Matsuda to the Japanese base in Batavia (now Jakarta) in the South China Sea, along with SS Lt. Col. Spielberger, who was traveling with mysterious cargo.
The voyage itself went better than expected. U-1324 mostly avoided enemy contact and even managed to torpedo a tanker. But their luck ran out near Batavia when a U.S. Navy patrol group picked them up on active sonar. Despite going silent, the sub took a brutal pounding from depth charges and went nose-first into the ocean floor. The forward torpedo crew sacrificed themselves sealing off the flooding compartment, but there was no way out. Ahbe released his men from their duties to the Reich so they could meet their end on their own terms.
While waiting in the dark, Ahbe encountered Spielberger—Matsuda had already committed seppuku earlier. As they faced their imminent death, Spielberger revealed he'd been transporting a painting: "The Twelve Knights Led by Brunhilda," supposedly painted by Hitler himself (it turned out to be completely worthless). Despite being a patriot, Ahbe wasn't a Nazi ideologue, and he didn't hide his contempt for Spielberger's refusal to think of his own family. Spielberger took this as a betrayal of the cause and killed him. Ahbe's loyal crew got their revenge.
Ahbe's story might've been one of heroic sacrifice, but Revy saw it differently—she was after his Iron Cross with Oak Leaves and Swords, a medal he'd earned fighting in the Atlantic. For her, it was just another way to make a quick buck.
Content compiled by AnimeList.moe from publicly available sources.
