The builders planned for the mayors of Ember to pass along a locked box, built to open automatically after 200 years, and successfully passed along until it reached the seventh mayor. Fearing he would soon die from a bad cough, the mayor tried to open the box. He was unsuccessful, and he died before he could return the box to its rightful place so that it might be passed on properly. As a result, the box was not opened after 200 years, and the supplies and plans the builders left behind are beginning to dwindle.
