This was one of my very favorites as a child, and quite complex for young adult literature, as it tells the story of a young girl who is essentially unwanted by everyone in her life after the death of her father. As her mother died in a freak accident when she was even younger, she moves in with her aunt and uncle, who also want to ship her off to boarding school. She becomes almost singularly obsessed with finding the Scottish Terrier dog she had in childhood, and goes on a city-wide search to find him, learning about both her parents, and herself, in the process.