Brennan is obsessed with looking for a way to bring his parents back from Terrenos. Mikey, now more distant than ever because of his parents' predicament, and Rya who still loves him are cleaning up Lore's remaining forces on Earth. The area where Lore tried to invade the Earth is cut off from the rest of the world by the government, but everybody still knows what happened.
The only important bit is that Brennan has a way to get his parents back to Earth, but he and an ally of theirs need to stay in Terrenos in their stead. After a bit of crying and a cringy selfie, it's hugs and kisses, then everyone retires to their homes.
That was a hell of an epilogue. By far the most boring. I dare say it's the only boring volume, though it tries to add some fights, a few 2-page vistas, blood and gore. All that soul-searching the characters go through is the definition of bore-fest for me. I already read how hard their lives were. They don't have to rub it in. Just walk it off!