The Stonewake Sequence

You find a vast granite door set into the cavern wall, its surface carved with interlocking dwarven rings and bright copper channels. Three rune plates sit in the stone like thick coin-sized wheels, while a shield-shaped socket rests at the center. Blue light crawls through the carvings with a sound like distant wind. Whenever anyone touches a plate, one of the symbols flashes and the chamber answers with a deep metallic tone. Frost gathers around the left plate, warm air breathes from the center, and a low tremor rolls beneath the right.