The Parables of Ancient Earth, Rephidim City of Reptiles

Rephidim City of Reptiles is the first book in the fantasy fiction Christian trilogy about a boy and his twin sister in an ancient world of Cyclopes, barbarians, and giant Reptiles. The boy is called on a quest by a tiny bird, an Olive Warbler, who promises to teach him true freedom while his twin rises to a position of power but is imprisoned physically in armor as well as mentally by her counselor, Pterodactyl Eri.