KEEP OUT said the bold, red letters on the green door. Sam felt it made clear that the door was worth getting into. He didn't read instruction manuals, either. A moment with his tools and the door let him in. That revealed a small office, a comfortable chair, a small rug, a small bookcase, and an old desk polished by use. The room was orderly but not overbearingly neat: a book canted against the reading chair's armrest, and a pen lay atop a few papers on the desk. Sam looked through the books and papers, leaving little disturbance behind.
He found the notebook inside the desk drawer, next to a pen gone dry. It looked like a journal to him, green with KEEP OUT in bold, red letters. Sam smiled. He wouldn't need his tools for this one. The inside cover declared in the same bold red NO EXIT. He turned the page.
The first entry began, "After the events of the following page..." Sam blinked, but read on. The author described breaking into a small office and rifling it, coming upon a private journal and opening it. Uncomfortable, he looked around and noticed text on the inside of the door: NO EXIT, red and bold. The next page began, "Then I returned to the previous page."
Sam felt the skein of the world peel back, and his rising panic subsided into a feeling of superiority as he picked the lock of the green door with the bold, red letters.