Description
The forest south of Haven is dying. Half the sentinels down there have turned to autumn, the spring ones no longer wake, and what comes up in their place is Hellbark - already burnt through before it ever breaks ground.
Groundskeeper Mattis has one season's worth of cure and refuses to spend it on a guess. He wants three readings taken from the wood, and then he wants you to tell him what is killing his trees.
Location
Floor 5 - Haven, at the tree line above the forest to the south. Mattis stands there himself; all three sample points are south and west of him, and take on a golden outline once he has set you looking.
Access Requirements
No level requirement. Entirely optional - it gates nothing.
Tips
There are three answers and only one of them is right. Mattis acts on whatever you tell him and he will not correct you, so read all three samples before you speak. He will accept a wrong answer, pay you less for it, and tell you plainly what it cost.
Rewards
Blightplate Outfit - Full addons, on every answer. This quest is its only source
Skill Potions - Three for the right answer, one for a wrong one

