Kaya dreams of racing her beautiful mare Steps High. Her father warns her that the horse isn't ready, but when a pesky boy insults Steps High, Kaya accepts his challenge to race. As they ride, Kaya loses sight of her little brothers. Her carelessness earns her a nickname that her friends won't let her forget.

In the fall of 1764, after Kaya and her sister are kidnapped from their Nez Percâe village by enemy horse raiders, she tries to find a way to escape back home.

Kaya is in awe of a young warrior woman named Swan Circling, who's so fearless, she doesn't even flinch when a runaway horse gallops straight at her! Swan Circling goes with the men into battle, bringing them fresh horses and tending to the wounded. If I were as strong as Swan Circling, Kaya thinks, I'd find a way to get my sister back. Swan Circling has heard the children calling Kaya "Magpie," the nickname she got for being irresponsible. Although Kaya has made mistakes, she wants very badly to be friends with Swan Circling. Will Swan Circling want to be friends with her?

When Kaya befriends a lone dog that has wandered near her camp, others in the village warn her to be careful. Dogs don't usually live by themselves, and some people think the lone dog is not to be trusted. But Kaya brings the dog food and can feel her gratefulness. After Lone Dog gives birth to pups, she lets Kaya be a part of her new family. When Kaya looks into Lone Dog's eyes, it's as if the dog is speaking to her. Kaya's grandmother tells her that if an animal speaks to her, she needs to listen. But as the pups grow older, Lone Dog has something else to say—something that Kaya doesn't want to hear.

Summertime means salmon fishing at thundering Celilo Falls—and horce racing, games, parades, feasting, and dancing, too! Kaya loves to join the fun, but she's also got something serious on her mind: searching for her lost sister, Speaking Rain. Thousands of Native American families and friends gather at Celilo Falls each summer, and Kaya hopes that someone may have word of her sister. Kaya's older sister, Brown Deer, is on her mind, too. Brown Deer will soon marry Cut Cheek, a thought that makes Kaya both glad and sad. She lost one sister when she had to leave Speaking Rain with the enemies. Now will she lose Brown Deer?

Speaking Rain has returned to Kaya's family, but Kaya still has one last fear—that she'll never see her beloved horse, Steps High, again. When Kaya hears of a heard of Nimíipuu horses running wild in the mountains, she hopes Steps High is one of them. Kaya soon has a chance to find out for herself when she joins the elk-hunting party traveling into the mountains. Kaya is filled with excitement and hope, but Speaking Rain is troubled by the smoke she smells on the wind—smoke from mountain fire. As Kaya searches for her beautiful horse, she has to face a fear greater than any she's ever known.