At the mention of Bai Guan, Wang Yang recalled the line Bai Guan had used in their drinking game.
Back then, Bai Guan had followed up with, "Kill and bury in darkened lanes; ruin the house and silence every mouth." It had only been a joke over wine, but jokes were the overflow of a person's disposition. Sometimes they revealed character, too. The limits a person observed in jest might well reflect the underlying color of his nature.
Thus, when Wang Yang heard that line, he had sensed a ruthless streak in Bai Guan, though the possibility of his being a Northern Spy had never crossed his mind.
Of course, from a bird's-eye perspective, as though playing a puzzle game, if he were told to pick the culprit from a fixed group of several dozen people and assured that the clues had already been planted, identifying Bai Guan would not have been so difficult. But in everyday life, he met so many people, heard so many words, and witnessed so many events each day. If Bai Guan's behavior counted as suspicious, then far too many people were suspicious. Through eyes intent on hunting spies, everyone looked like a spy. This was what psychology called the mental set effect.
Upon hearing that it was Bai Guan, Hu Xiezhi immediately moved to send troops to arrest him.
Wang Yang stopped him and asked three questions.
First, aside from Xiao Qi's confession, there was no evidence proving that Bai Guan was a Northern Spy. If they arrested him, found no corroborating evidence, and Bai Guan refused to confess, were they prepared to torture a confession out of him?
Second, if Bai Guan headed the spy ring, he must have subordinates. Aside from the four riders who had rescued Liu Yin, were there other