You open the door to Room 3. You walk inside and notice you just made a mistake. A live chain saw is floating in the air like there is an invisible person holding it! You don't really need encouragement to run for your life, so that's exactly what you do. You dash back to the door and run into the hall, and you run to the first room you see, which is Room 2. As you get to the door, you turn around and see the door to Room 3 cut in half by the chain saw!
Get in Room 2 before it is too late on Chapter 22.