The Orchestron Vault Door

The vault door is a masterpiece of brass and copper, six feet in diameter and flush with the stone wall. Three concentric rings revolve around a central glass eye, which casts a golden beam onto a nearby pedestal. The smell of old grease and warm metal hangs heavy, accompanied by a rhythmic ticking that sounds like a massive heartbeat. Every few seconds, the rings shudder as if trying to complete a rotation, but they remain locked in place until the correct sequence is entered.