Meg is 14-years-old. Everyone sees her as a troublemaker (a person who makes/causes trouble). They think she’s a bad student. Everyone in her family seems to be perfect. Her mom is a very beautiful scientist. Her twin brothers are very athletic. And her little 5-year-old brother, Charles Wallace Murry, is a child genius and can often read the mind of Meg.
One night Meg can’t sleep. She goes downstairs to find her young brother sitting at the kitchen table drinking milk. Later their mom joins them. A strange neighbor called Mrs. Whatsit joins them. Mrs. Whatsit is talking a lot and says that the “tesseract” is real. We (the readers) don’t know what this means, but Mrs. Murry knows what it is. She looks like she is going to faint (fall down from sickness or fear).
Meg and her brother meet a friend the next day. Calvin O’Keefe is a high school junior student. Together, the three of them go to visit an old haunted house which belongs to Mrs. Whatsit. While going there they meet Mrs. Whatsit’s friend, Mrs. Who. Mrs. Who is also very strange. Meg and Calvin begin to like each other. Charles suddenly announces that they should focus on finding their father who is lost somewhere in the universe.
Strange things happen and the older women turn into supernatural (not from Earth) beings. They transport the kids to the universe by the “tesseract.” They stop and visit different planets on the way. The women tell the children that the universe is being attacked by the “Black thing” (the devil).
They find out where Meg’s father is being kept. Charles tries to use his psychic (in his mind) powers to see where their dad is. Eventually they find their dad, but not without drama. Along the way, Meg learns to love. She uses this new love to help them escape.