Meg, Charles Wallace and Calvin return to the Murry home for supper. Calvin calls his mother, even though he thinks his family does not care about him. He likes the Murry family and house, and when he sees a picture of Meg's father he asks where he is. Meg doesn't want to answer, and Mrs. Murry gets Meg to help Calvin with his math homework. Calvin is surprised at how smart Meg is. He is happy to have met Meg and her family.
After supper Meg and her mother talk. Mrs. Murry says how much she misses her husband. She also explains that Charles Wallace is different from other children, although in what sense he is different is hard to put into words.
Calvin and Meg go outside for a walk. Calvin asks her about her father, saying there are rumors that he left her mother for another woman. Meg is upset by this, but Calvin says he knows it is not true. It turns out that Meg's father is a physicist working for the government on a top secret project. Meg knew he was traveling a lot, but she does not know where he was sent. At first he wrote every day, but then the letters stopped coming. Mrs. Murry has tried everything she knows to find out where he is, but all she is told is that he is on a secret and dangerous mission. Meg starts to cry, and Calvin comforts her. They are interrupted by Charles Wallace, who announces that they are going to find their father. Mrs. Who and Mrs. Whatsit mysteriously appear. Then a third voice is heard, and Charles Wallace says it is Mrs. Which, but she does not materialize completely.
Meg's ability to solve math problems by using short cuts foreshadows the short cuts through time and space involved in the concept of tessering. That in turn rests on a practical application of Einstein's concepts of the nonlinear nature of time. This is also foreshadowed in this chapter by the mention of Einstein by name, in the context of his famous equation from the Special Theory of Relativity, E = mc2. By hinting at these concepts now, the author is carefully preparing the reader for the adventures that are soon to take place.
This chapter also emphasizes once more how different Charles is, and how dissatisfied Meg is in being who she is. It also introduces the last of the three ladies. Mrs. Which is distinguished from the others by the fact that she does not fully materialize.