Luna, a cougar cub, lives comfortably in a den with her mother and brothers until a fall down a steep hillside and into a river separates her from her family. Luna has never hunted by herself before, and alone in the forest, she must call on all of her instincts to survive. Her long journey home is filled with danger. She is stalked by a wolf. She gets in between a mother elk and her calf, and she is discovered by humans. But Luna perseveres and learns how to take advantage of everything in her environment. Young readers will thrill at Luna's adventures while they learn how these iconic creatures adapt to a changing world.