The Instructions were in the metal box that was set to open in 200 years, typed by the Builders. it was to be passed down to each mayor who were entrusted to not open the box. But after one sickly mayor tries to open it with a metal hammer thinking there was something inside that could help him (it did not open), it was tossed to the side. After his death no one remembered the box. The instructions told the people of ember how to escape from the underground city to the world above.