He cautiously peered inside and saw that Huang Sen had actually opened a hidden door in the study on the first floor, revealing something significant within.
Because the hidden door closed in an instant, Zhang Yi couldn't see clearly what was inside, no matter how sharp his gaze was.
He quietly climbed back in, walked into the study, and found a syringe in the trash can.
Afterward, he took the syringe to someone for testing, which confirmed that the liquid inside was an ultra-strong sedative.
This concentration is enough to take down an elephant!
Thus, Zhang Yi could conclude that Huang Sen must have imprisoned Zhan Qiang behind that hidden door and had been using sedatives on him for a long time.
So, after confirming this, Zhang Yi immediately went to Bai Cheng'an to inform him of the situation.
