Who could have silently placed the letter on An Shuli's carriage?
An Shuli's carriage, besides having a coachman, also had guards. It's clear that the person possessed no small skill.
Upon opening the letter, the content of Su Zishe's letter was extremely arrogant. If Su Zizhan hadn't sent a message to Yun An in advance, and he hadn't already had an idea of what to expect, this letter would have infuriated him to the point of reaching nirvana.
He clenched the letter in hand and said to An Shuli, "Have you checked everyone around you?"
"As soon as I saw this letter, I immediately checked!" An Shuli sighed. "This letter seemed to appear out of thin air. Even the Hidden Guards in the shadows didn't notice it, saying they saw no one approaching the carriage."
Yun Chi narrowed his eyes slightly, "A letter appearing out of nowhere isn't impossible."
An Shuli looked at Yun Chi, "Your Highness means..."