In the first official trailer for Split, three girls in a car look over to see a strange man in the driver's seat, and tell him they think he has the wrong car. But instead of leaving, he abducts them. In the place they are taken to, they find flowers everywhere. They notice a woman through the crack in the door and call for help, but the "woman" is actually the man who abducted them.
We then see him sitting on their bed and say he is a nine year old boy. A psychologist is shown saying that the abductor is named Kevin and that he has 23 different identities. Kevin tells the girls that a beast is coming for them and they attempt to escape, before he does something horrible to them.