|Min Coin: 99s, 67c|
Max Coin: 1g, 10s, 97c
In the secret room behind the library is a crystalline statue (-25, +13.5, +32)
Inspecting the statue will trigger a quest for you to go and kill 2 Everling Caretakers. There is a room with 3 of them just off the eastern hallway of the 2nd floor, right near the library. The quest literally takes 30 seconds. If you've made it down to the library, this should be a snap.
The reward is 1g5s97c and the Caretaker's Bludgeoner.