After the soldiers left, the second prince got up from the ground and looked at Duan Qinwang, who was locked in the opposite cell. He sneered and said, "You said everything has been arranged. Is this how you arrange things?"
Duan Qinwang knew that Emperor Yong'an must have sent someone to monitor his every movement, so he didn't react when he heard the second prince's words. Instead, he went back to the corner of the cell, lay down on the bunch of straws, and pretended to be asleep.
When the second prince saw Duan Qinwang ignore him, he became angry and wanted to scold him. However, before he could speak, he saw Duan Qinwang lightly tapping the wall with his index finger.
The meaning is clear. The walls have ears.
After realizing why he was ignored, the second prince calmed down and sat on the straw in the corner of the cell. Now that things have become like this, he can only wait for opportunities and act by ear.
