C220 Hidden Ace

An hour later, the "Dr Sun" returned to the fourth floor.

Walking out of the staircase 'Dr Sun', he smiled and nodded towards the two guards not far away from the staircase, then walked inside, this was also a common practice.

However, before he could even take a few steps forward, he suddenly heard a sound behind him, "Eh?"

Dr Sun's body trembled unnoticeably