Letter from the resident mage

Letter from the resident mage is a letter and a quest item in .
It is found and read during the secondary quest Greenhouse Effect.
== Journal entry ==
:Lesbeth,
:I'm very flattered by your interest in my humble greenhouse and naturally will describe to you how it works. Believe me - I've nothing better to do here. The witchers, being witchers, are tight-lipped, and even when they do finally say something it's rarely anything very interesting. But enough of my complaints, let's return to the greenhouse.
:"Greenhouse" is, of course, merely a term of convenience, for this construction does not require any structure that could be called a house - it consists of three monoliths made of magic-absorbent stone (basalt is best, or porphyry, but granite will do in a pinch). The monoliths must be arranged in a triangle, and then charged with energy from the elements of fire and water.
:Since a triangle has three vertices, there is no way to lay out the powers symmetrically - and that is precisely the point. The unstable arrangement will strive towards equilibrium according to the principle of the conservation of magic energy. Heat is a side effect of this process - and so, as they say in Beauclair, voila!, within the triangle conditions become like those of a greenhouse, favorable to the cultivation of exotic plants.
:Two last remarks. First, charging all three monoliths with the same element will accomplish nothing – the arrangement will be stable and there will be no flow of energy. Second, the arrangement will naturally lose its charge over time and thus must be checked up on regularly – especially bearing in mind that once equilibrium is achieved, the temperature will fall and heavy precipitation will result, following the ancient principle quod magia facit, natura laxit.
:That will have to do for now. Your Hieronymus.
:PS. Perhaps by way of thanks you could come visit me? True, the witchers have made me swear on all that is holy not to reveal where Kaer Morhen lies, but you, my dear, dear Lesbeth, can be trusted.
== Associated quest ==
* Greenhouse Effect
Category:The Witcher 3 books
Category:The Witcher 3 quest items
de:Brief des örtlichen Magiers
pl:List czarodzieja rezydenta
fr:Lettre du mage résident
it:Lettera del mago locale