The First by Katherine Applegate

To learn if she truly is the last dairne in the world—the endling—Byx and her friends must travel into the snow-covered mountains of the country of Dreyland, where they hope to uncover the truth behind the legend of a hidden dairne colony. But the threat of war across the lands continues to grow with each passing day.

As the group confronts untold dangers at every turn, they will ultimately uncover a treacherous plot that involves the other powerful governing species. With both her dreams and all the creatures of Nedarra on the brink of extinction, Byx and her friends are determined to never give up hope.