Wentzel Ahbe was a highly-decorated U-Boat captain in the Kriegsmarine, who had survived many a depth-charge battle during the Battle of the Atlantic. In March of 1945, he led U-1324 out of Kiel, Germany on one last mission: transport Lt. Col. Matsuda back to the Japanese base in Batavia (now Jakarta), in the South China Sea. Ahbe did pick one other passenger... SS Lt. Col. Spielberger, who was carrying an unknown cargo with him.
For the most part, U-1324 was remarkably lucky: it ran into few enemy, as well as torpedoing an enemy tanker. But just as it was near Batavia, it ran into a U.S. Navy patrol group and went into silent running. They may have made it... if the group didn't use their active sonar. U-1324 was hit hard by the depth charges, and as a result was drove nose-first into the ocean floor. While the forward torpedo crew managed – at the sacrifice of their own lives – to seal the rest of the sub from their flooding compartment, there was no way they could escape their fate. It was then when Captain Ahbe had relieved his crew of their duties to the Third Reich... so that they could face death in their own manner.
While waiting for his end, Captain Ahbe met Lt. Col Spielberger (Lt. Col. Matsuda had already committed seppuku, a.k.a. ritual suicide, earlier). It was then that Spielberger, after imploring Ahbe about the chances of escape, revealed he was carrying a painting... "The Twelve Knights Led by Brunhilda" allegedly painted by Adolf Hitler (in actuality, it was later revealed years later to be a meaningless painting). Although Ahbe was a patriot, he was not a Nazi, and had told Spielberger openly about his disgust about not thinking about his family, which he was. Spielberger was offended about Ahbe's lack of loyalty to the Nazi cause and murdered him. Spielberger was later killed by Ahbe's loyal crew.
Although Ahbe's story was of a heroic fighter, Revy didn't have any compunctions about seeking Ahbe's Iron Cross with Oak Leaves and Swords, which Ahbe earned during his tour of duty in the Atlantic, which she only sought as something to get a quick buck.