Rin swims away from the burning research base after Altan’s sacrifice, exhausted, wounded, and tempted to let herself drown. Altan’s remembered voice drives Rin onward, ordering Rin to follow the Phoenix constellation southeast toward Speer, while the Phoenix calls to Rin and the ghostly Woman warns Rin to stay away.

As Rin drifts between life and hallucination, Rin’s spirit seems to move through visions. Rin sees a stormlike god, Chaghan and Qara near a broken dam, and a past moment in which Mai’rinnen Tearza refuses to sacrifice the world for Speer. Rin also encounters Jiang, who appears as something ancient and powerful; Jiang anchors Rin long enough to command Rin to wake before drowning.

Rin reaches Speer and crawls onto sand filled with bones, realizing Rin has landed in the graveyard of the slaughtered Speerlies. Following Altan’s imagined commands, Rin finds an overgrown stone path to the ruined temple, then discovers that the true shrine lies underground beneath the sand.

Inside the silent subterranean temple, Rin enters a trance before the Phoenix’s carving without needing poppy. Mai’rinnen Tearza blocks Rin again and warns that surrendering to the Phoenix means eternal burning, but Rin rejects the warning. Tearza explains that Tearza once chose to burn away Tearza’s own power and give Speer to the Red Emperor to prevent the world from burning; Rin condemns this as cowardice and destroys Tearza’s spirit with flame.

Rin confronts the Phoenix and asks for the end of the Federation. The Phoenix refuses to call Rin’s path destiny, insisting that Rin chose every step that brought Rin here and that any disaster will be Rin’s responsibility. Rin chooses revenge anyway, dehumanizes the people of Mugen, promises worship and blood, and commands the Phoenix to burn them all.

The Phoenix makes Rin a conduit for divine fire. Rin experiences unbearable internal burning as the fire tears through reality and annihilates the island of Mugen, killing millions of civilians as well as soldiers. Unable to bear the guilt, Rin shuts away the part of herself that would recognize those deaths as lives; afterward, still overflowing with uncontrollable fire, Rin drags herself from the temple and collapses on the sand.