User blog comment:Simplyme/Fading?/@comment-4142691-20110909234524

I think Apollo mentioned they faded as he drove the demigods and hunters to CHB in the Titan's Curse. Though it might be possible that Selene is chilling somewhere. Most likely with Endymion in that cave on mount Latmos or in Helios' golden palace in the east. Their mother is lurking around there as well according to myths at least. Theia used to be attending Helios, must've sucked, being bossed around by her own son xD