Dr. Brown lived near the Grand Canyon and frequently took trips to study it. He also studied the Grand Canyon with a leading expert at Arizona State, but this professor preferred not to deal with the origin of the canyon. Dr. Brown often pondered the mechanism that must have formed this great canyon, one of the seven wonders of the natural world. He studied maps of Utah and Arizona and suspected that a huge lake, or a series of lakes, had breached their natural boundaries and carved the canyon in a few weeks. He realized that a fault had to be in a certain place if he was correct, but the state geologist, a man Dr. Brown once had supper with, checked his files and found no fault was there. (A fault is a crack in the ground along which the opposite sides have slipped in relation to each other.)