The phantom hourglass of Zelda seeks answers from the master.

1. When you reach the dark Hailar city and enter B6, talk to the map on the wall. At this time, Link will take out another map by itself, then turn off NDS and turn it on again, and your map will be printed with logo. Then go to the gun island and ask the person who gave you the gun for the mechanical arm.

2. After the game is over, you will get a bomb package according to the needs of the plot.

3. After you get the mechanical arm, go to the sign printed on the map on the B6 floor of Hailar City in the dark to salvage it. You will get a key, and then you can open the door.

Just think about it yourself. If not, you can view the policy. I wish you a successful customs clearance.