The unexpected meeting with Mister Chares upset Khan but also gave birth to worries that couldn't be ignored.
The Headmistress had great power inside the Harbor, but Mister Chares had still managed to enter it and meet Khan. That was no easy feat, especially for someone without a massive political influence. His apparent anonymity only worsened that problem, adding a layer of suspicion that forced Khan to consider him a real threat.
However, the study that unfolded once Khan returned to his flat didn't lead anywhere. Even involving Monica and George didn't change that situation. According to the network, Mister Chares was no different from the average political figure. He wasn't even a Patriarch, which made everything more suspicious.