The Portcullis Mechanism

Summary

The Portcullis Mechanism is a complex mechanical system located in the cavern beneath The Rex Tree. The mechanism consists of three carved stone buttons mounted on the wall that control multiple portcullises throughout the chamber, as well as the door at the top of the tree itself. In Session 3 of the campaign, Safia discovers the mechanism while attempting to free Sucks, Katniss, and Vasso, who had been trapped behind one of the portcullises. The system's design appears intentionally constructed to trap sacrifices within the cavern complex, as opening one portcullis prevents the upper door from opening.

Properties

The mechanism features three carved stone buttons positioned on the cavern wall. These buttons control at least three separate portcullises within the chamber through a linked mechanical system. The buttons must be pressed in a specific sequence to operate correctly, requiring careful observation and trial-and-error to decipher the proper pattern.

The mechanism operates on a principle of mutual exclusion: opening certain portcullises causes others to close or bars the door at the top of The Rex Tree. As the GM explains, "You're looking at the buttons and you're looking around the room and you can sort of see logic in where things are placed and how like these three portculli and the wall and the door in the side of the tree, how it's all kind of part of the same mechanism." This interconnected design suggests the system was deliberately engineered to trap individuals within the cavern complex once they enter deeper into the chamber.

When activated, the portcullises raise into the ceiling with a series of audible clicks. The door at the top of the tree produces a distinct "thunk" sound when it becomes barred, providing feedback about the mechanism's state.

History

Session 3

Safia encounters the Portcullis Mechanism after Sucks, Katniss, and Vasso become trapped behind a portcullis in the cavern beneath The Rex Tree. She examines the three buttons and the chamber layout, attempting to understand the logic of their placement. The GM notes that Safia can observe how the three portcullises, the wall, and the door in the side of the tree are all part of the same interconnected mechanism.

Through careful observation, Safia deduces that opening the portcullis trapping her companions will prevent the door at the top of the tree from opening. The GM confirms, "And you think that if you open this portcullis you won't be able to open the door at the top of the tree."

Despite this realization, Safia proceeds with freeing her trapped companions. She successfully deciphers the correct sequence through trial and error: "You push the button in a specific sequence. That takes a lot of trial and error. And the portcullis. Click, click, click, click, click, click, click. Raises into the ceiling. And you hear a thunk up further in the tree that you believe means the door has been barred."

The activation of the mechanism successfully frees Sucks, Katniss, and Vasso, but simultaneously traps the entire party deeper within the cavern complex by barring their exit through the upper door.