The moment Simon saw this intruder, he had several guesses as to the intruder's identity and goal.
He could start listing them out but the list would be far too long.
He had a few reasons as to why he came to the conclusion that the intruder was related to the factions and that the goal of the intruder is to see how he cures the poisoned traitors.
Firstly, only the factions would have enough reasons to implant a spy in the Iron Fangs.
Second, Simon asked himself why exactly would the factions choose to risk the life of one of their own.
No matter how powerful the factions were, a spy's life is always in danger because he or she would be in enemy territory.
Unless the factions truly saw him as a serious threat, Simon had a hard time believing that the factions would send a spy to infiltrate the Iron Fangs for no reason at all.
And that was when it clicked for Simon.
His poison.
