Treason against the Light (光への反逆 Hikari e no Hangyaku) is the eighteenth episode of Phi Brain: Kami no Puzzle Season One and the eighteenth episode of the anime series overall.
Following the incident, Cubic and Ana start avoiding Kaito, believing they can no longer follow him, much to the dismay of Nonoha. Meanwhile, Gammon, who is contemplating whether he should become a Giver, becomes concerned that the POG may start targeting Nonoha. He calls Kaito and Nonoha out, saying that they should stay away from each other. When they object, Gammon challenges Kaito in a puzzle of his own design, in which they must attempt to trap each other in laser walls. After Kaito uses his Orpheus state to solve the puzzle, Gammon walks off and decides to become a POG Giver.