Yes, the adults do come back in the Gone series.
The Return of the Adults
The overarching narrative of the Gone series involves a mysterious dome that traps everyone under the age of 15, creating the "Fallout Alley Youth Zone" (FAYZ) and leaving them isolated from the adult world. Ultimately, this dome does come down.
Impact on Survivors
With the collapse of the dome, the normal order is restored for most of the world. However, the experience of being trapped within the FAYZ fundamentally alters the lives of the children who survived. Their journey through the FAYZ, facing unimaginable challenges and changes, leaves a lasting impact on them, even as they rejoin the adult population.
