In the state of Jìn 晋 in the Chūnqiū春秋 period (period 04d), there lived a great general named WÈI Jiàng 魏绛, who went off to war and remained away for fifteen years.
Also in the state of Jìn there lived two officials. The civil official, named ZHÀO Dùn 赵盾, was virtuous, but the military official, named TÚ Àngǔ 屠岸贾, was evil. The virtuous Zhào and the evil Tú were enemies.
A neighboring king gave the king of Jìn a miraculous but vicious dog (shén'áo 神獒), which was passed on to the evil TÚ, who trained it to attack a dummy dressed as Zhào. When the dog was fully trained, Tú started a rumor that there was a traitor in their midst, and that the dog was capable of detecting the traitor.