Desmond doesn't need to know about the library because they are looking for ways to save the end of the world. In the library, the golden apple projected an image and showed it to Sergio. In fact, it was the memory machine that showed this to Desmond indirectly. Desmond knew where he had to go to save the world, so he went to the United States to find the hole at the beginning of 3, because there was a way to save the world in the hole (but the way found at the end of 3 was really pitted by Juno). . . —_—)
How did the landlord say that they knew the location of the hole? Because at the end of the day, the earth model projected by Apple told them. Did you hear the end of the apocalypse? The animation of the plot was over. Desmond finally said, I know where we should go.
The first power source, it is estimated that the pioneer left it in the hole on purpose. . After all, the pioneers have calculated everything ~ the power source should also be an artifact, after all, they left it.
I wonder what else the landlord doesn't understand? I can communicate with you ~