After getting rid of the Kobolds Macaroni and I were planning on going back to bed while Gimdalf finished the second half of his shift. However, when I entered the tower the mystery tome* in my bag began to glow. Upon opening it I saw all the unreadable ancient text had vanished and was replaced by a diamond shape and a dot with a short line of unreadable text. As I moved around I noticed the dot followed my movement and eventually found that the diamond shape indicated the centre of the room. It would bug me to go to bed at this point so I removed the floorboards to see what was underneath it the tome was indicating. Of course, that stupid Gimdalf kept trying to see what was going on with the book the entire time, while Macaroni just went to sleep. Seeing the round centre with plates fanning out I immediately suspected it was some sort of secret staircase. These things usually have a trigger somewhere but as I was tired I couldn't think of what this trigger could be.
The next morning I went to claim the reward for the Kobold's on my own while I left Gimdalf and Macaroni to figure out how to activate the stairs. As I left they were hammering away at something and the mystery tome in my bag seemed to react to the sound. As I went to the foreman I noticed the Dragon's tooth quarry seemed to have been restored to some extent overnight. When I asked the foreman about it they said they didn't know why that was but it always happened. They also told me that a popular legend about this phenomenon was that a giant dragon had been slain here in old times.
As I received the payment for the Kobolds, 3 gp and one super fancy smooth rock, I was still pissed about Gimdalfs Hypocrisy and suggested the foreman should solve the Kobold problem at the root by finding out why they steal and teaching them how to make their own equipment. It's more cost-effective in the long term and they might get something unexpectedly good out of it. They thought it was a decent idea although at first, they assumed I was suggesting exterminating the Kobolds' nest.....
Because of the rock, I was in a much better mood when I returned to the others. Macaroni and Gimdalf hadn't gotten much further than that the staircases all seemed to sound differently, this tower was built much later and that under the walls of the tower was a ring with the same ancient symbols as there were in the mystery tome. Upon making another loud sound, I felt the mystery tome vibrate again so I opened it. There were no additions other than a static symbol in the left lower corner. As none of us could figure out what it meant I simply poked every symbol that appeared while the other two were trying to figure out the effects of different sound pitches. Eventually, the tome seemed to be done with it and manifested blue glowing arrows (with text none of us could read) which is how we discovered one of the symbols could slide over a line and that was the trigger to lower the stairs. While Gimdalf and I were standing on a safe spot that would stay level with activation, Macaroni fell down along with all the furniture in the room.
The staircase led to a big underground room with nothing but a broken door that led to a hallway. There was an obvious trap area halfway this hallway. Gimdalf used a floating disk for Macaroni and I and, after almost falling into the pit trap himself, climbed along the wall on his own accord. At the end of the hallway was another door, this time in decent condition, that led to a practically empty room with only a burned piece of wood covering what Gimdalf identified as the skeleton of some ancient thing that has long gone extinct. The weird thing was that a chasm had cut off part of the room but this cut was in an extremely straight line. There is a possibility that this is a small part of what used to be a rather large underground building so we decided to investigate.
*Mystery tome: a tome made of an unidentified metal inscribed with ancient texts. Identification does not work on it and it seems to have no magic of its own. It was taken from the crazy druïd in Eorls Gedreas.