I stopped reading this book for a while before I finished it. Sandy and Dennis were my least favorite of the Murray children when I started the book. In A Wrinkle in Time the two perceive themselves to be the men of the house and their father's absence and admonish Meg for fighting because they believe it's something boys should do. Aside from that, their gardening, and their close bond, they didn't have much character development. They are characterized as the skeptics of the family, not at all open to creative thinking. As the novel progresses, we get to see that change and we get to see Sandy and Dennis characterized as individuals instead of halves of a unit, and I've come to really like their characters. They're kind to the mammoths, and the way the mammoths are characterized to be almost dog-like makes me love them. Overall, this was a fantastic look at the least talked about Murray children and an exploration of their characters when put into wild situations.