After returning home, I immediately went to Arin's location and asked her what she's intend to do with the Vampire King.
"For now, it's best for them to think that the enemy is the cult and not all humans. Because of those traitors, they must be discussing about whether they will join us in destroying the cult or not. And someone who refused it could be seen as another traitor. If the Vampire King is smart enough, he should know that. Also, if some of them left before we meet him tomorrow night, those vampires might be with the cult. Why don't you send some people to watch the castle and track anyone who left in a hurry?" Arin suggested.
…Is she a genius? She's way too smart.
"I'll talk to Albert right away," I said as I was about to call Albert.
"Oh, and it's best if you make a move. Meet the Vampire King himself and show him your strength and your goal. That might persuade him to join us tomorrow," Arin said.
