Get Help from Healer Nettie is a quest that is part of Find a Cure. After entering Emerald Grove for the first time, the Tiefling Zelvor will tell you about a healer namedNettie.
Nettie is located inside the Emerald Grove to the northeast. Head north from Zevlor and go northeast, going around to reach some stairs going down. A scene will play with some Tieflings being refused entry, which indicates you are in the right place.
You can begin the Save Arabella quest before approaching the druids, though it's not part of this quest.
If you started the Save Arabella quest, you must resolve it before finding Nettie. If you haven't spent enough time with Shadowheart, bringing her along will accelerate her quest line.
Follow Nettie into the other room, then tell her about your symptoms. She will give you a vial of wyvern poison but only if you swear to take it upon feeling symptoms. If you refuse to swear and reject the vial, Nettie becomes hostile. She transforms into a boar to fight. Hold her off with a tank and attack from a distance to win.
Loot the body for Bottle of Silvanus (cures all poisons) and the Key of the Ancients, which gives you Nature +1. This is the first resolution for this quest.
If you didn't talk to Rath and get the quests about finding Halsin, you get them now and learn the same clues needed to find him. This is the second resolution for this quest.