The beauty of R.L Stine 'choose your own adventure' books is that he ensures that the most improbable and interesting scenarios are available for the reader to choose from. Outstanding in this particular genre. It's all about Denny who runs off by himself in the huge Museum of Natural History. So, you go look for him...because you are guiding the story, but, instead you find the laboratory of the crazy Dr. Peebles. There is a time machine and suddenly Denny runs into it and vanishes. All the instructions are at the bottom of each page, you make the choices. If you don't find Denny in two hors he will cease to exist. This is the second book in the Give Yourself Goosebumps Gamebook series.