Deeper Fibula Quest/Spoiler

Required equipment

 * Key 3940

Method

 * Head to Fibula and enter the dungeoun through the well.
 * Follow the path shown on the map. If you are faced with a locked door, you need Key 3940 to open, it can be bought on the island.
 * Upon coming down, head east and through a teleporter.
 * You will now be faced with two teleporters, go to the right one, and head through the level 50 gate of expertise.
 * When walking through you will come to a room with quite a lot of minotaurs and a few minotaur archers.
 * Continue west through fire, and energy fields to get Key 3980, be prepared to face Minotaur Mages.
 * Key 3980 is found by "useing" on a hole to the west (marked on the map).
 * Go back and then south, unlock the door with you newly found key, and in the next room, prepare to face several minotaurs of sorts.
 * Continue further and now prepare to face Dragons and Dragon Lords.
 * The quest rewards are found in scattered human and skeleton corpses at the end of the cave.
 * The portal in the south-west part of the last room leads back to the dungeoun entrance.