On the Teltain, Futtor insists that they must leave Sunsa now that Ypsilon has been recovered. Arron and Gurran reply that their mission take precedent. Ypsilon must be allowed to fight Chirico again, and they must stay to observe.

On Rochina's ship, Chirico fine-tunes a Scopedog and writes himself a new mission disc containing everything he knows about the maneuvers of a PS. Fyana speaks with Chirico, admitting she is afraid for him, but he counsels her to accept what must happen. Ypsilon is fighting out of loneliness, and will not stop until one of the tem is dead. Ypsilon, meanwhile, renews himself with a jijirium bath and launches for the surface in a new Strikedog.

On the other side of the galaxy, Melkian General Karmeny meets with Battentain to discuss the implications of what has happened in the Nonaggression Zone. Battentain is shocked to learn of Rochina's defection, and admits he never quite knew how to read the man. Despite the risk to the peace treaty, a task force of Gilgamesh battleships must be sent to Sunsa with Rochina as their target.

Chirico crosses the Sunsa desert to Siguray Crater, where Ypsilon's empty landing craft stands waiting. Chirico takes the bait, and the battle is joined! This time there are no distractions; the two clash with each other time and again. Chirico's mission disc works perfectly, allowing him to match Ypsilon move for move. Rochina takes notice and finally announces to Fyana what he has suspected all along: that Chirico is a true Perfect Soldier! And at long last, Chrico fires the fatal shot that takes Ypsilon down!

Before he can finish Ypsilon off, however, Chirico is interrupted by Fyana, who gives him the shock of his life - that he is more than human. Chirico insists that his mission disc is what allowed him to win, but then notices that the disc burned itself out only a few minutes into the fight. From then on, it was his own ability. Ypsilon insists in his final moments that Chirico has to be a PS...Ypsilon's pride would not allow him to die at the hands of a normal man.

Later, Chirico prepares to leave Sunsa, Rochina's words echoing through his mind: "You are a PS. You want proof? Then go to planet Quent. There you will learn everything."

"What was it that lay hidden in my past? I'd fought Ypsilon and won. But I couldn't believe it. There was no way I could be a PS. The Planet Quent...what awaited me there?"