Phaersis is one of many slaves found in the Cloakwood Mines during Baldur's Gate. He's a bit more courageous and knowledgeable than most slaves, willing to risk telling Gorion's Ward about potentially Flooding the Cloakwood Mine - despite not having anything to do with the actual quest.
"Psst... there be a plug somewhere that seals this mine from the river's torrent. Find it and maybe you can render this hell no more than a watery memory of its former self."
- 1: Where is this plug you speak of?
"I know not, only that Davaeorn is said to have the key upon his person at all times."
- 2: This is the only mine between Baldur's Gate and Amn that is still produced valid ore, however horrible its method. Much as I would love to flood these fetid walls, we might yet need more than memories of this place.
"And what of Nashkel? Is their ore not still light and strong? Fie, I can tell by your face that I have been entombed within this grave too long! My world has staggered on without me..."