In Chapter 5, Charles Wallace defines the tesseract as the fifth dimension—the square of time, which allows one to travel great distance without time passing. The novel’s title is a reference to this process, which is shown by Mrs. Who. She folds a wrinkle into her skirt, much as a tesseract creates a wrinkle in the timestream. Mrs. Whatsit, Mrs. Who, and Mrs. Which have much experience with the tesseract and make the process smooth for the children. By contrast, Mr. Murry barely understands how to tesser, which results in Meg almost dying. The tesseract represents how technologically far behind the Earth is compared to other parts of the universe. Mr. Murry’s inexperience with the tesseract traps him on Camazotz. In the hands of the more experienced, the tesseract becomes the vehicle of his rescue.

The tesseract also represents Meg’s fear. Meg does not tesser well, even with the help of the Mrs. Ws. She also dislikes the process. In Chapter 4, the Mrs. Ws sweep the children into a tesseract without warning. Meg panics, and her panic doubles when she realizes she’s alone in a void. She senses no other presence and feels utterly alone.