Space Pirate Captain Harlock

The Witch's Ocean Castle of Death (1x13)

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The Arcadia heads back to Earth to investigate a third signal being emitted from the Sargasso Sea. There, the witch Aman, who was waiting for the Arcadia, wages an attack using a 1945 Imperial Japanese naval ship. Harlock, curious as to how this phenomenon occurred, sets off to investigate at the bottom of the sea.