Guardian: The Fifth Gate

Zhao Yunlan worked as the Chief of SID, a special office that worked in odd cases that had not normal explanations, nor can be solved in the common way by the Police Department of Dragon City. That's what the cops were told, so was the public, but what the people don't know is that is just a cover of the members of the Order, establish right after the times of gods and that their real job is to capture or kill those things that occasionally come out from one of the four gates, to keep their people safe and oblivious of the threats of the old world.

However, there was a legend about a fifth gate, that even the Order has forgot, as it's seal had never been breached since the gods walked on Earth. Thus when a new case about missing students in a Museum, working in the restoration of artifacts recovered from a recently found old tomb, both Zhao Yunlan and Professor Shen Wei, leader of the restoration project, found themselves immersed in said legend that traps them inside with no return. Will there really be no way out of the fifth gate or the gods will help them back, to once again seal it, this time eternally?

BAD ENGLISH, but an interesting tell. I don't own Guardian, that rightfully belongs to Priest.