Soldier sister, fly home

Half-Navajo, half-white sisters Tess and Gaby are separated when Gaby drops out of college to join the army. Now as Gaby is deployed to Iraq, she asks Tess to care for Blue, the spirited horse that Tess dislikes. Tess struggles with her identity and with missing her sister, and she decides to spend the summer with her grandmother at sheep camp where tragedy strikes.