Summer 1979

In 2002, the Marine Express is preparing for its maiden voyage beneath the Pacific, linking the United States and Japan by an unprecedented underwater railway. Suspicious that the project may be hiding illegal activity, its chief engineer hires private detective Ban Shunsaku, only to be murdered before he can explain what he knows.With only a glimpse of the killer to guide him, Shunsaku boards the train and begins investigating among its passengers. The deeper the Marine Express travels, the more the murder becomes entangled with secrets surrounding the railway itself, transforming a technological celebration into a dangerous mystery beneath the sea.

After the war with the Comet Empire, the Yamato sets out on what should be a routine training voyage with new cadets aboard. Elsewhere, Dessler returns to the ruined planet Gamilas, where an unexpected disaster threatens both his people and neighboring Iscandar.The Yamato is pulled into the emergency as a new enemy arrives seeking valuable resources. What begins as a peaceful new departure becomes another desperate mission, forcing former enemies to confront a threat that could erase the last remnants of worlds already devastated by war.