Speaking of keys, Ma Lu remembered that Seta had also given him one last time, it was an Earth Dragon tooth, similarly associated with the Secret Treasure.
When Ma Lu left, he had thrown it into the storage point, and this time he brought it with him, adhering to an attitude of trying his luck.
Upon checking his pockets, he found the Earth Dragon tooth again, but when he got to the stone door, there was no reaction, nor did he see anything resembling a keyhole on the door.
"Hey, could there be many rooms that store the Secret Treasure? Each room corresponding to a different key?"