After the two police officers put Qin Kong in the police car, Officer Liu then turned to Tang Qing and said:
"Come, you two should come with me to the station."
He had seen Qin Kong talking passionately to Tang Qing earlier, and while Tang Qing seemed completely uninterested in engaging with him, since Tang Qing knew Qin Kong and was a 'witness at the crime scene', it would be proper for them to go back to the station to give their statements.
Moreover, he speculated on why the Superintendent would personally call them, specifying that they should handle Qin Kong's case 'impartially'? And who was the one who reported the crime to Zheng Xiu? A regular person's call would never reach Zheng Xiu, and even if the county received a report, it's impossible for the Superintendent to notify them. So, someone must have directly asked Zheng Xiu to step in.
So who was this person?
Or...was this a set-up by the Superintendent?