The Murry family was like any other family, or at least that’s how it seemed. The youngest, Charles Wallace and the oldest, Meg had special powers that would help them later on. One day, during a Hurricane a woman named Mrs. Whatsit came into the Murry’s home for shelter. She was an old lady, but she moved very quickly. The next day, Charles and Meg went for a walk and met Calvin O’Keeffe, a boy in Meg's class at school, by Mrs. Whatsit’s house and they all went inside.
Then Mrs. Witch, another old lady, tessered them to a planet called Uriel. Tessering is like if you were on a long string, you would bend the string to get to the end of it quicker. While on Uriel, they see the black thing. It is the thing everyone in the universe is fighting (including their dad who disappeared months earlier.) It made everyone feel sad and lonely. Then Mrs. Witch tessered them to Camazotz where they met the man with red eyes who hypnotized Charles Wallace. When Hypnotized, Charles didn’t care about anything except IT. IT is Camazotz's leader.
It is pretty much a giant brain.
Afterwards, they find their dad trapped in a transparent column and take him to a different planet where they meet “Aunt Beast”, a hairy tentacle monster who helps them regain their strength. Finally, Meg goes alone back to Camazotz to save Charles by finding the only thing IT doesn’t have and that is love. Finally, they all get back home safely. The end!