Cai Wei said: "After Nangong Shi's failed coup, he fled to Liaodan with his subordinates and has been plotting his comeback ever since. I happened to bump into him in Liaodan and captured him. This is a good opportunity for you to interrogate him thoroughly and root out all his conspiring allies within the court."
Her analysis was entirely correct. It was after receiving a secret letter from Nangong Shi and learning that Cai Wei had been kidnapped by Saknu that Li Kaifeng started to observe the Emperor in the Imperial Court closely.