In the new world, there is a whole city underground, some parts of which are connected by passages sealed with doors. Each pair of these doors has a unique key that must be found in order to unlock them.

This will greatly facilitate the movement of dwarves around the city, as the walls are made of a special stone that is very difficult to work with.

The residents of the city all have the keys to these doors, allowing them to move freely and suddenly appear in front of anyone who enters the city without permission. This makes research on the city more difficult, as it is necessary to find the keys before moving further.