[6] The plot centers about the drama which ensues when a stray proton missile, from a battle between the Galman Empire and the Bolar Federation, crashes into the Sun.

Over the course of the story, the Yamato and crew must complete their mission of finding a new home for Earthlings amidst the strife caused by the Galman-Bolar conflict.

The Yamato and crew eventually catch up with Desler, who is deeply remorseful that Earth has been dragged into this conflict.

It turns out that she is worshipped by peace-seeking factions within both the Galman and Bolar empires, and is wanted (preferably dead) by both governments which fear her influence.

Earth is finally saved when the Yamato brings Ruda to Shalbart, and she decides to give the Earthlings a device (the Hydro-Cosmogen Gun) that can restore the Sun's natural fusion balance.