"Boss it looks like that zero already goes outside of the dungeon. Unfortunately, we did not notice him and there could be a chance he already went out of the inner area.
But don't worry, I already sent some people to wait in front of the entrance and some other people will be present in front of the Guardian Association. During all this time I will be staying in front of the Goblin Dungeon."
Sometime later one of the subordinates of Kevin contacted him and told him that they were unable to find any kind of clue of Zero. As you know only when anybody wanted to enter the dungeon then they would need to show their ID, but it is completely different when they wanted to come outside of the Dungeon.
Because of this, they would not be able to get any kind of information from the Guardian Association. With these, they decided to divide their group. Only like this, there is a possibility they would be able to find any clue about Zero.