C19 The Closed Loop

Shen Ann's heart was filled with anticipation, thinking that Chen Nannan would bring him to some secret place.

However, when they arrived at the destination, Shen Ann looked at the door that was wrapped in iron chains with a puzzled expression.

This was the top floor of the laboratory building in Central District.

The two of them stood on the staircase, one on top and the other on the bottom