Quest for the Carlin Graveyard key

I don't know this quest, but a friend of my told me he found a book that said, "This was a bad day! I lost my key to the crypts below while I was fishing in the port. This is especially bad because those trolls hid my precious trumpet somewhere down there.". This book is a clue for this key. I've herd that it was locked in a room somewhere in Tibia too. But this is all the informantion I have for this quest so far.