Various Assumptions

Lin Jin recognized this wooden plate. Or perhaps it was more appropriate to say that he had seen many just like it thanks to the visitors of his Visitation Hall.

Be it He Qing, Black Crow, or even Feng Ziqian and Zhao Jingyan who showed up more recently, they each had a plate, on which a number was carved, which corresponded to the door which they entered the Visitation Hall through.

This should be the key to the Visitation Hall.

Carved on this wooden plate was the number 'three'. It just so happened that doors number one to three had never been opened before. The first visitor to enter the hall was He Qing who came in through door number four.

At first, Lin Jin found it strange, but now, he was able to come up with an explanation.

He Qing had come in through door number four because the tokens of the first three doors had been lost. 

Of course, there were other possibilities aside from them being lost. Much more investigation had to be done.