in faust’s study, the poodle changes into the devil (mephistopheles). faust makes an arrangement with the devil: the devil will do everything that faust wants while he is here on earth, in exchange faust will serve the devil in hell. faust's arrangement is that, while mephistopheles is serving faust, if faust is so pleased with anything the devil gives him, that he wants to stay in that moment forever, he will die that very moment (in german he says: “verweile doch, du bist so schön” – “stay a while, you are so beautiful”. it is perhaps the most famous quotation in all german literature.)