Meg Murry is a bright but struggling teenager, grappling with the mysterious disappearance of her father, Dr. Alex Murry, a renowned scientist who vanished four years ago while researching an enigmatic concept known as a tesseract - a wrinkle in the fabric of time that enables instantaneous travel across the cosmos. Meg lives with her mother, also a scientist, and her prodigious but peculiar younger brother, Charles Wallace. At school, Meg endures bullying and feels out of place, her father's absence weighing heavily on her self-esteem and family life.

One evening, Charles Wallace introduces Meg and her classmate Calvin to three celestial beings: Mrs. Which, Mrs. Whatsit, and Mrs. Who. These enigmatic figures reveal that they have come to help Meg find her father, who is trapped on a distant planet, under the thrall of an all-consuming darkness called the IT. A perilous journey ensues as the celestial guides lead Meg, Calvin, and Charles Wallace through the tesseracts, challenging them to brave strange worlds and confront their deepest fears in the pursuit of rescuing Dr. Murry and restoring harmony to their family.