Forgotten woods

Requirements

 * Feeding Cassie quest is done
 * Fairy Grove was discovered

The trade
If you talk to the Fairy Queen about the massive plant just outside of her grove, she would agree to share information... in return for some unique food she can't taste otherwise. Unlike standard gifts one requires to give her when summoning, there's no limit of how many attempts can be made.

The queen would reject most items you can offer her, not even considering them (there are special comments if you attempt to give her Bottled Bug Venom, Fertility Pill, Golden Apple, Meat Tendril or Weird Fish). However, she would accept the Cheese or Cheese Slice (either normal one or Your Cheese), as it's indeed a new experience for her and other fairies.

The fairies would be too busy munching to pay attention to you, but when you leave the Fairy Grove, another fairy would reveal you the one and only weakness of the Giant Plant: there's a very conspicuous and very vulnerable bulb one can... rub, to make the plant leave; however, it would return eventually. It's so blatant, in fact, Lust Doll would wonder how they've missed it before.

Deep forest
The path to the north is locked by another Giant Plant, with its bulb being on the other side. Choose another path for now.

When you go to the west, you would run into a tribal hunter, who would run from you further to the west. Follow him (remember that you can disabled Giant Plants by rubbing the bulbs) right until you pass through the mushroom field. When he follows to the east by passing another plant, instead of following him, backtrack and go through the northern entrance, which would force the hunter to move to the east instead. When the hunter would disappear, search for a hidden entrance in the northern part of location.

Once in the village, you have to pass a series of Speech checks to convince the villagers that you're not an enemy (they're suspecting you to be an agent of someone called "plant mama", or suffer a "torture" (by various voodoo dolls) before they decides that you're innocent after all. Regardless of outcome, the villager leader (a large woman who introduces herself as Nymosa) would agree to talk to you, revealing that she's somewhat familiar with your language.

Nymosa can be asked on several topics: her village, her language, the "plant mama", the mushroom and her god, Polkopola. From now on, you can also approach the hunter (whose name is Nymph), albeit there's nothing you can do for now, not even talk.

This is where this quest ends for now