Meg Murry is a teenager who is having problems fitting in at her high school. Meg's brother, Charles Wallace, is also different. Not only can he speak like an adult, but he also always intuits what Meg and her mother are feeling and thinking. Meg's mother is a beautiful scientist who cares for her children, but misses her husband, who disappeared a year ago. Meg loves her family, but hates that they seem odd and don't fit in.

Meg is awakened one night by a huge storm. While sharing a midnight snack, the Murrys have an unexpected guest, a Mrs. Whatsit. She is an oddly dressed old lady who casually tells Mrs. Murry that there is such a thing as a tesseract. Mrs. Murry is frightened. The tesseract was something she and her husband were working on before he disappeared.

The next day, Meg and Charles...