Lord Withermoore's Soul Jar Edit
To begin the quest Lord WIthmoore's Soul Jar you must enter the Cavern located in the first two images on the right. Once inside find and interact with the child Mody, once you have, play along with his game until he asks to play Hide n' Seek, agree to it. His locations are in images 4 and 5, after you have found him the second time he will take you to the location in image 6 where he will tell you about his friend, Lord Withermoore, after seeing that you are too large to crawl through his entrance he tells you to dig yourself to him and a pile of dirt will appear beside you, you will need a Shovel or a Lizard character to enter Lord Withermoore's chamber.
Once you have entered the chamber follow the path down to where you will find Mody and Lord Withermoore in his petrified state. Talk to the petrified Lord Withermoore and he will tell you about how he was tricked and trapped, afterwards he will request that you pull the spear from his side (You will need a Strength character to pull it out.), upon removing the spear he will de-petrify and wish to speak to you again, requesting your aid in freeing his soul from the decaying skeletal form he now is.Lord Withermoore explains of a secret hatch that will appear after interacting with the teleporter statue in the main courtyard. A hatch will open right next to it which will take you to the Underground (this seems to be in the prison itself).
The first room has a teleporter shrine and a locked door. The lever for this door is located behind the tree that sits across the shrine and between two broken vases.
Clear out the cells and find the key on the stool. This will enable you to go up a floor where there are a bunch of Silent Monks. They are neutral so there is no need to worry. At x316 y673 you will find a secret lever that can be pulled which moves the desk near it revealing another hatch leading to an Ancient Passage filled with traps. You can put the nearby vases on the vents to disarm them.
Following the passage will lead you to a room filled with different Withermoore Soul Jars. The one you're looking to break is Withermoore the Supplicant. The others will spawn enemies, or elemental traps. You can choose to leave the soul jar alone, absorb the soul (gives the character who does a single soul point and the team 4000xp each, and you get to keep the empty soul jar), or smash it on the ground. Smashing the jar gives the highest xp (5600 each) but does not give a soul point. This frees the soul of Withermoore and updates your quest log.