On a dark and stormy night, twelve-year-old Margaret Murry sits on the foot of her bed in the attic and watches the storm. Except for her, everyone in the house, including her twin brothers Sandy and Dennys, and her baby brother Charles Wallace, is asleep. Meg has had a bad day at school and cannot stop thinking about it. She is also upset about the fact that her father has gone missing.
The dog Fortinbras barks, and Meg remembers hearing about a tramp in the neighborhood who stole twelve sheets from Mrs. Buncombe, the constable's wife. She wonders whether the tramp is heading for their house. She goes downstairs to make cocoa and finds five-year-old Charles Wallace in the kitchen. Charles Wallace says he knew she would come down, and Meg wonders how he knew. Charles Wallace always seems to be able to tell what she is thinking.
Everyone thinks he is dumb, but Meg and her parents know that is not so.
Mrs. Murry joins them in the kitchen. Meg no longer feels fearful, and her mother tries to encourage her not to feel so bad about herself.
Charles Wallace mentions someone called Mrs. Whatsit, and says she and her two friends live in a house in the woods that is said to be haunted.
Fortinbras growls, and Mrs. Murry goes to investigate what has upset him. Meg thinks it must be the tramp. Her mother returns with someone who does look a bit like a tramp, and is all bundled up in clothes. It is Mrs. Whatsit, who was out in the storm and realized she was passing Charles Wallace's house and thought she would stop by and rest. Meg is suspicious of this old woman, but makes her a sandwich anyway. Charles Wallace chats...