Meg, Charles Wallace, and Calvin return to the Murry home, where Mrs. Murry huddles over her Bunsen burner, preparing a dinner of thick stew. Calvin calls his mother to tell her that he will not be home for dinner, though he tells Meg that he doubts his mother would have even noticed his absence. Calvin is deeply moved by the warmth and love that permeates the Murry household, and exclaims to Meg that she is very lucky to have such a wonderful family life.
Before dinner, Meg shows Calvin a picture of her father with a group of scientists at Cape Canaveral. She also helps him with his homework. Calvin is surprised to learn that Meg, who is several grades below him in school, is able to help him with his math and physics. Mrs. Murry explains that Meg's father used to play number games with her when she was a child, thus teaching her all sorts of tricks and shortcuts.
After dinner, Calvin reads to Charles Wallace in bed while Meg sits with her mother downstairs. Mrs. Murry expresses her grief at her beloved husband's absence. She tells Meg that she believes that things always have an explanation, but that these explanations may not always be clear to us. Meg finds this notion troublesome because she likes to think she can understand everything. She comments that Charles Wallace seems to understand more than everyone else, and Mrs. Murry says that this is because Charles is somehow special.
In the evening, Meg and Calvin go out for a walk in the Murrys' backyard. Calvin asks Meg about her father, and she explains that he is a physicist who worked for the government first in New Mexico and then at Cape Canaveral. Meg tells Calvin that the family hasn't heard from their father for a year now, and Calvin alludes to all the rumors that the townspeople circulate about Mr. Murry's whereabouts. Meg becomes immediately defensive, and Calvin is quick to assure her that he has always doubted the rumors' truth. Calvin holds Meg's hand and tells her that her eyes are beautiful; Meg feels herself blushing in the moonlight.
Charles Wallace suddenly appears, announcing that it is time for them to leave on their mission to find Mr. Murry. Mrs. Who slowly materializes in the moonlight and Mrs. Whatsit scrambles over a fence, wearing Mrs. Buncombe's sheets. Then, in a faint gust of wind, their friend Mrs. Which announces in a quivering voice that she, too, is here, but will not materialize completely, as the process is too tiring and the little band has much to do.
As in the previous chapter, Meg is troubled by all that she does not completely understand. Her first challenge in the novel is to learn to accept not knowing everything. For example, when she first meets Calvin, she immediately wants to form a definitive opinion of him, but her mother urges her to be patient and insists that in time she will come to know him better.
Meg must learn that reality is not always as it seems, a lesson that applies to her father's disappearance, her brother's extraordinary gifts, and her own self- conception. The theme is reinforced at the end of the chapter when Mrs. Which decides to remain invisible, yet her presence is nonetheless certain. It is Meg's particular challenge to learn to see things more clearly, as they truly are, beneath their often-deceptive surfaces. Thus it is significant that so many of the important characters in the novel wear eyeglasses: Meg points out her father to Calvin as the man in the photo with the glasses; Calvin tells Meg that she has gorgeous eyes behind her glasses; and Mrs. Who's thick spectacles are the first part of her to materialize in the moonlight. The theme of seeing clearly is reinforced later in the novel, when Meg is about to alight on Camazotz with Calvin and her brother; Mrs. Who's parting gift to Meg will be a pair of glasses.
Calvin, too, learns that things are not always as they seem. He is surprised to learn that Meg, although a few grades below him and generally considered a moron at school, is able to help him so much with his homework. Calvin asks Meg several questions about modern physics, all of which she answers readily; ironically, however, she misses the obvious question about the author of Boswell's Life of Johnson. Especially significant is the question about Einstein's equation for the equivalence of mass and energy, for it points to the ideas that influenced L'Engle more generally while she wrote her book: as L'Engle read the latest works of Albert Einstein and Max Planck, she incorporated their ideas about relativity and quantum theory into the conception of time she presents in Chapter Five.
The overarching theme of the book, the power of love, permeates the entire chapter. Calvin remarks that although his mother never seems to notice him, he nonetheless loves her dearly. Likewise, Mrs. Murry tells Meg that she is "still very much in love" with her husband, even though he has been gone for so long. Calvin is deeply moved by all the love in the Murry household, and remarks that the neighbors who invent stories about Mr. Murry's extramarital affairs do so because they "can't understand plain, ordinary love when they see it." Finally, Calvin and Meg's budding romance is also a testament to the power of love even amidst adolescent awkwardness: we read that the moonlight glistens on Meg's orthodontic braces and her glasses become stained with tears; yet in Calvin's eyes she appears beautiful.