Luke is not yet 12 when his father dies of a heart attack, leaving him an orphan. Small for his age and something of a loner, Luke goes to live with his Uncle Henry and Aunt Helen in Collingwood on Georgian Bay, where Uncle Henry has a saw mill on the edge of town. The practical Uncle Henry sees that the family dog, Dan, is old and lame and no longer useful, and he concludes the dog should be destroyed. Luke, whose sense of dignity and loyalty transcend the practical, fights to save his dog, and in his struggle, he comes to a better understanding not only of Uncle Henry, but of the expedient world of adults.