A book has disappeared from the classroom shelf. Chloe, Ella, Harry, and Owen were the only ones in the room. One of them took it. Exactly one of them is lying.

1. Chloe says: "Owen took the book."
2. Ella says: "I didn't do it."
3. Harry says: "I'm innocent."
4. Owen says: "Neither Chloe nor I took the book."