Ten-year old Millie Powell's father, a Klondike Gold Rush stampeder, is missing. Millie and her mother arrive in Dyea, Alaska in November 1897 to search for him. Devastated to learn of his accidental death, Millie wants only to return home to Victoria. While her mother works to earn money for their passage, Millie resents the difficult living conditions and fears they'll never leave Dyea. She struggles to find a sense of belonging until she meets a young friend, Thomas, and his dog Rosie. When Thomas heads up the Chilkoot trail with his uncles, he leaves Rosie in Millie's care until spring.

Disaster strikes in April – an avalanche kills many climbers on the trail. The tragic reminder of how Millie's father died prompts her mother to decide it's time to go home. Activity in Dyea slows once the gold seekers move on, but Millie has found reasons to stay. As departure time looms, she plots to persuade her mother to relocate instead to the growing town of Skagway, and to embrace their new way of life.