The unreal child thing is confusing, I grant you -- I may rework that bit. In this 'verse, the "empty child" isn't a child who's been wrongly healed by nanogenes -- he's a manifestation of the end of the world. All the energy of the rift fracture has poured into him, and they can't time-travel until he's either dissipated or destroyed. And if he isn't, he'll destroy the universe. FUN! :D