Cepheus Lost

Bryden grew up on a strange world, enchanted by the light of its moon and the glowing nevaeh trees. In this forgotten village, Bryden's sister Cayala has suspiciously disappeared into the valley that the townspeople have not dared enter since their ancestors' original climb up the cliffs to safety.
Bryden, his brother Dak, and his friends T and Kylun will have to brave a world controlled by the deadly Krog in an attempt to save the lives of Cayala and the villagers. Before this journey is over, the four young adults must face the secrets in their town's past and those found within this new world while dealing with a relentless, warring species bent on conquering the galaxy. But they will also discover a world that they have only dreamed of as they confront the Krog.
For Bryden and his friends, it will take all the courage and determination they can muster along with a great deal of luck to survive. But one thing is certain-the descent into the mysterious, misty valley will change their lives forever.