Piper and Alistair, twins tasked with logistical assessment in the Historical Archive, discover a critical link between water flow and acoustic stability. They find the Tinnitus device, a miniature silver tuning fork meant to control the main reservoir flow valve via a specific sound frequency. They learn the device requires the Cartographer's Compass to activate its resonance. This connects their logistical investigation to the physical artifacts found earlier by Cora and Finnian. The episode ends with the twins realizing the Tinnitus device is pointing them toward the Great Clock Tower, suggesting the Cartographer's Compass artifact is located there, where the silver general was previously found.