The Curse of Frogs
The Amber Temple is a secret vault of magical artifacts and information located somewhere in the Balinok Mountains. You are not sure exactly where it is located, but you know the path there begins at the Tsolenka Pass and continues up the slopes of Mount Ghakis.
in Argynvostholt told you the temple was built in the ancient past by a secret society of good-aligned wizards, trying to contain objects of great and terrible power. They, their gods, their knights, and their spells ultimately failed. When Strahd came into the Temple, He emerged from it stronger and more terrible that before.
Costello in the Abbey warned you that the temple was a perilous place, a trap for adventurers, tempting them with riches and power and ultimately murdering his entire party. He warned you against going there — and if you do go there, he warns you against accepting any dark gifts.