Derek and the underground adventure

Previously

…He noticed small indentations, cleverly disguised as part of the design, near the levers. They were perfect for fingers, or perhaps something else entirely. The circular disk in the center was divided into segments, each bearing a different symbol, some of which he recognized from the surrounding wall. He tried to move one of the levers, a thick, stubby protrusion to the right of the disk. It was stiff, unyielding. He applied more pressure, straining against it, but it wouldn't budge. He felt a surge of frustration, quickly followed by a wave of self-reproach. He was being foolish, rushing in without thinking. This was clearly