Spielberger, a native of the German city of Stuttgart with a wife and daughter, was a member of the Nazi Party's elite Waffen SS during World War II, was ordered by Alfred, at the time his superior, to be the guardian of a tableau painting titled 'The Twelve Knights Led by Brunhilda'. With authorizations issued by the SS, Spielberger managed to find passage onboard the U-boat U-1324 as it left the pens at Kiel; the boat already escorting Lt. Col Matsuda back to Japan-held Batavia in Indonesia (now Jakarta).
Unlike Matsuda, who openly socialized with the U-1324 crew, Spielberger rarely left his quarters. But the only time he did, it was to voice his objection over Captain Wentzel Ahbe's decision to torpedo a British carrier in the Indian Ocean, stating that doing-so would not change the war's outcome. Ahbe was shocked to hear Spielberger's tone of defeat, but continued the attack, stating that unless he heard from his superiors otherwise, he and his crew would continue to fight to the very end.
The voyage was uneventful until the U-1324 was miles from their objective. There, the sub found that a U.S. Navy patrol was on the surface, searching for Japanese submarines. Despite firing a torpedo to divert the patrol away, one destroyer remained above, forcing Ahbe to take the U-boat into silent running. Then the destroyer used its active sonar, afterwhich it fired its depth charges, sending U-1324 into a nose-first dive to the ocean floor – one that it would never surface from.
After learning from his surviving crewmembers about the dire circumstances of their situation, Ahbe relieved them of their duties to face death in their own way (Matsuda had already committed seppuku by then). After retiring to another part of the ship to contemplate his death, Ahbe met Spielberger, who demanded when they would be surfacing. After receiving the bad news, Spielberger then told Ahbe of his mission, which was to deliver the painting he was carrying and hide it until the Nazis were once again in power. By now Ahbe was disgusted by Spielberger's defeat, and told him openly that maybe his sub's sinking may have been God's will for everything his crew sacrificed themselves for, as well as his disgust of having to share a coffin with the likes of the SS officer.
Offended, Spielberger then ordered Ahbe to retract everything he said, for which Ahbe continued to calmly rail at his antagonist. Finally, Spielberger took-out his Luger and shot Ahbe twice in the head, killing him. He then tried to commit suicide himself, but then the U-1324's crew, hearing the shots, charged-in to get revenge for Ahbe's murder. Spielberger managed to kill three of them before getting shot himself.