In the opening chapter of "A Wrinkle in Time," we are introduced to Meg Murry, a high school student who struggles with feelings of inadequacy and isolation. Meg is depicted as an intelligent girl, but she feels out of place among her peers and is burdened with worries about her father's mysterious disappearance. Her family dynamics are explored, introducing her mother, Mrs. Murry, who is a scientist, and her siblings, including the exceptionally bright Charles Wallace and the twins, Sandy and Dennys.

The chapter sets a somewhat somber tone as Meg grapples with her self-esteem and the challenges she faces at school, including bullying and a lack of support from classmates. It is clear that she is deeply affected by her father's absence, which has left a void in their lives. The narrative captures her inner turmoil and her affection for her family, particularly for Charles Wallace, who is portrayed as a peculiar yet brilliant child with an extraordinary understanding of the world around him.

The story takes a turn when a strange visitor arrives at their home during a stormy night. This visitor is introduced as Mrs. Whatsit, a peculiar old woman with an eccentric appearance and a mysterious air about her. Her unexpected arrival raises eyebrows, and the family is initially uncertain about her intentions. Meg and Charles Wallace are intrigued yet cautious while their mother seems to have an inkling about Mrs. Whatsit's significance.

As Mrs. Whatsit settles into the Murry household, she hints at the existence of a tesseract, a concept that intrigues and confounds the children. Her cryptic remarks about the universe and time set the stage for the fantastical elements that will unfold throughout the novel. The mention of a tesseract serves as a pivotal point, suggesting that there are dimensions beyond their current understanding, and foreshadows the adventure that lies ahead.

The chapter concludes with a sense of curiosity and anticipation, as Meg's initial skepticism gives way to wonder about the possibilities that Mrs. Whatsit represents. The themes of individuality and the struggle against conformity begin to emerge, laying the groundwork for the challenges and growth Meg will face in the coming journey. Overall, this chapter serves as an essential introduction to the main characters and establishes the emotional and thematic foundation for the adventure that is about to unfold.