Wei Shou 魏收, author of the Wei-shu 魏書 (the Dynastic History of Toba Wei), left behind a historical riddle: What were the underlying causes of Ts'ui Hao's 崔浩 tragic end? Just as some scholars have done with many other historical events of the same period, this article tries to answer this particular question. In Part One an analysis is made of the characteristics of steppe civilization as it existed in the society in which Ts'ui Hao lived. These tiny yet insoluble particles, which attached to a culture, were possibly the indirect factors which brought about this historical tragedy. Ts'ui Hao, who had lived under the influence of agricultural civilization, attempted to reform a community which was a mixture of steppe and agrarian cultures. In so doing he clashed with the ruling power. Hence his downfall and execution. Part Two of this article discusses this clash and the various problems arisen out of it.