While you make your journey into the Underdark, you may stumble upon the Myconid Colony and there will be a fugitive hiding there.
The fugitive is a Deep Gnome named Thulla, who had recently escaped the Duergar, a species of Dark Dwarf that has enslaved her people.
Thulla is being hunted by the Duergar and just before she escaped, she was cut by one of them and unfortunately for her, the blade was poisoned.
Where To Find Thulla?
Thulla can be found at the Myconid Colony in the Underdark, which is located around the northern part of the Ebonlake Grotto.
Thulla will be lying on the ground squealing with pain near Sovereign Spaw, who is providing her with the colony’s protection.
How To Cure Thulla?
To cure Thulla, you will need to speak to her to begin a cutscene, and choosing the right dialogue will end up with you curing her.
This can be to give her an Antitoxin or a Potion of Poison Resistance but passing a check for knowledge on Duergar Poison works too.
If you run into the Duergar called Gekh Coal, you can obtain a cure from him as well if you are unable to use other methods.
Additionally, you can cure Thulla with a Lesser Restoration spell cast either by a character or with a scroll spell.
Rewards For Curing Thulla
If you help Thulla out, she will reward you by giving you the Boots of Speed, which provides you with the option to use the Click Heels action.
This provides you with double movement speed and freedom of movement, which causes enemies to have a disadvantage on opportunity attacks against you.
The Boots of Speed are also considered as a quest item needed for The Missing Boots Quest given to you by a Duergar named Gekh Coal.
Verdict
Thulla is part of a group of Deep Gnomes that are forced to dig for the Duergar and will ask you to help them, which starts the quest called Save the Grymforge Gnomes.
If you are after the Boots of Speed, saving Thulla is the easiest way to get them as stealing them from her or killing her would result in you facing the Myconid Colony.
Before doing any other quests, it is important to cure Thulla or else she might disappear later on when you come back or look for her.