Abandoned Tunnels

You cross the bridge onto the center raised platform, then enter the tower. Inside, you find a dusty room. There's a skeleton in the corner, but no other signs of life. It looks as if the owner of this building died here long ago. As you explore further, you find schematics for all kinds of technologies which have long been kept secret by the government. You find blueprints of the palace and other major governmental buildings. Finally, you find a letter on the skeleton. It's short, and written in a shaky hand.

"I am the last of the first revolution. We failed. The Rat King raided our base and executed most of our leaders. Only I escaped. They surely have hidden our existence from you. Please, continue our legacy."