Among the most skilled and dedicated of the Watchers was Erina, a lithe and keen-eyed young woman whose senses were finely tuned to even the slightest disturbances in the subterranean depths. From her strategically positioned outpost, she monitored the flows of underground rivers, the rumblings of the earth's movements, and the faint whispers that echoed through the tunnels - secrets known only to those who dwelled in this shadowy domain.