Heading west to Fort Walla Walla to take religion to the Indians, with her mother and minister-stepfather, 12 year old Emily McGregor suddenly finds herself alone after a brutal attack on their wagon train. An ugly white man posing as an Indian is the culprit and promises to return for Elizabeth and make her his bride. Sad at losing her precious mother and frightened of the threat made by the man, Emily wonders what to do next. Her thoughts are interrupted by a baby's cry. Happiness to find someone else alive is short lived when she realizes she does not know how to take care of a baby - especially a boy baby. By morning another orphan arrives - Clara, a black girl about the same age as Emily who has also been left alone under similar circumstances. Together they decide to push westward and as far away from Old Grisly [the name Emily has given to the ugly man] as they can go. Emily's concern is not for herself but for the baby. On their journey they encounter the elements, lack of food and milk, wild animals and Indians before they find help along the trail.