First arrive at the Doomsday Hammer in the game map and enter the gate directly, which is [Doomsday Hammer-North Zone]. After entering [Doomsday Hammer-North Zone], there is a patrol physical monster at the door, and there is a patrol monster in the legal system who will walk around the audience and pay attention to avoid it. After the physical patrol monster goes to the right, take another step to the left. After the battle, I came to the library gate under the North Gate Square. The door is locked. There are three ways to open it. After opening the door, walk along the passage to the end to reach [Doomsday Hammer-Library].