Xue Yan didn't know that Prince Yi had something on Duan Huai, so Jiang Yue naturally didn't ask. Instead, she said, "Then let's wait for news. Once we find out that those three people took Doctor Shen to Changyu, then that means Prince Yi must have used Duan Huai."
The deduction just now was based on Prince Yi's foundation in Changyu.
Xue Yan agreed.
…
It had been almost a day since Doctor Shen had been taken away before Xue Yan and Jiang Yue found out about this matter. They sent people to investigate on all the roads. Fortunately, Doctor Shen was found in one of those carriages. He was old and could not afford to travel day and night, so he tried his best to buy time. In addition, Xue Yan had specially instructed the Cloud Guards and the Dark Guards to pay special attention to the road to Changyu. As a result, it only took a day for the Cloud Guards and the Dark Guards to find traces of Doctor Shen here and there.
