神鬼难测

Explanation: Measurement: speculation. It seems highly secretive, Bourne is also unpredictable degrees. Guess no one can describe. 　　Source: Ming Luo, "Three Kingdoms" eighty-seventh back: "Zhujiang are Baifu said: 'the prime minister Machine Operators, Bourne unpredictable'." 　　Examples: This little dragon tiger Tao, ~. ★ Ming Anonymous "cutting Qi Jin Xing" fourth fold