After asking, Shen Yijia immediately frowned. "This letter was sent at the right time. Does that mean that the person who sent the letter saw everything we've done recently?"
This was also what Song Jingchen was thinking. This letter came after he kidnapped the old prince.
At least the other party knew what he was investigating and that the old prince was currently in his hands.
However…
"Regardless of whether the other party is a friend or foe, if what it says is true, the old prince should also be kept in the dark," Song Jingchen said.
Now that he thought about it, the reason why they found out about the Fragrant Teahouse was because of the information provided by the old man who fished. After that, it was the undergarment that came out of the Fragrant Teahouse with a special fragrance. These seemingly small clues pushed him to investigate further.
Also, someone must have deliberately exposed the female corpse of the Wutong River.