One of the key characters is Charles Wallace. He is Meg's little brother, and he is highly intelligent but also a bit naive which gets him into trouble. He is initially able to communicate with the Mrs. in a special way. Meg, as I said before, is the main character whose journey is the focus. She has to grow from a self - doubting girl to a confident hero. Calvin adds the element of friendship and a different perspective. And the Mrs. Whatsit, Mrs. Who, and Mrs. Which are the ones who set the whole adventure in motion and provide the necessary guidance.