When her grandmother dies at the age of 96, 12-year-old Emily faces a double loss – no adult in the family wants the Saskatchewan farm where her grandmother spent her life, and it seems it will be sold. In her grief, Emily visits a rock on the farm that she and her grandmother loved. There she meets a Scottish girl named Emma Elliott, who is dressed in odd clothing. Gradually, Emily realizes that Sentinel Rock can transport her back to the pioneer days of the 1890s. But why?

This question occupies the rest of the book, and is played out on many levels. Emily travels back and forth between the melancholy present, where she and her mother put her grandmother’s house in order, and the past, which she visits over just a few days in her own time, but many months in Emma’s. Emily is able to teach Emma some of her grandmother’s herbal remedies. These soften the harsh realities of pioneer life, but ultimately cannot change Emma’s fate. The reader will probably make the connection between past and the present long before Emily does, but don’t be fooled. The plot is more complex than it initially appears.

Silverthorne’s descriptions and dialogue are sometimes discordant, but her evocation of the late 19th century is vivid. The clever use of time travel may even entice kids who don’t like history into a more sympathetic understanding of the past. The author does not quail at showing pioneer life for what it often was – nasty, brutish, and short. But Emily learns a lesson from the past that she can carry into her future, and perceptive young readers may too. This is a sincere, well-plotted book.