Ines Galiano 
Forest’s Edge [EPUB ebook] 

After the Black Years, the citizens of Civis, inhabitants of the caves took refuge underground and made a Pact with the inhabitants of the greenhouses, in the city of Silva. And so began the second era of civilization and still today, four hundred and fifty years later, the Pact is still observed. Vogel is one of the fifty-two apprentices beginning his period of instruction in Civis, but the forest has other plans for him.