Canticle

Canticle is the first book of the Cleric Quintet by R.A. Salvatore.

"High in the Snowflake Mountains sits the Edificant Library, a place of scholarly study for priests, bards, and others. Now from the hidden vaults beneath the library a devastating curse is unleashed, and a young cleric must battle the terrifying creatures set loose by a malevolent, consuming essence."

Summary
In this novel, the Wizard Aballister Bonaduce creates the Chaos Curse, a horrible potion that makes people need to fulfill their deepest most personal desire without regard to the consequence. A priest of Talona, Barjin, takes the potion from Aballister and brings it to the Edificant Library, an enemy of Castle Trinity, where Aballister and Barjin work. Barjin makes his way to the library, sneeks into the cellar of the building, and is able to release the ever-smoking potion unto the library with the unknowing help of the priest Cadderly. The library deteriorates into pandemonium, but Cadderly, his good friend Danica Maupoissant, the two dwarven brothers Ivan and Pikel Bouldershoulder, and a druid named Newander travel down to the altar of Barjin and kill him, saving, for a time, the library.

Audio book
An audio book version of this novel exist, with an introduction by R. A. Salvatore, explaining how it came to be, fan response, and other information about it.