There's an in game puzzle you must solve in order to make it into the Abbey.
The high altar in the Abbey has unique visions for Clerics when they touch it:
[Misenseor Abbey, High Altar Chamber]
Wavering light produced by several glowing braziers offers enough illumination to make out discernible shapes. A series of thirteen stone columns thrusts up from the black marble floor, the tops lost in the inky darkness high above. Arrayed in a sweeping arc, these great columns stand like a ring of guardians, bringing focus to the high altar that rests upon a raised dais. As if tended by unseen servants, this place of power has remained in pristine condition despite the passage of time. You also see an ironbound door.
The altar has been cut from a single block of deepest black obsidian and is devoid of ornamentation. Standing in resolute silence, bearing witness to many unspeakable acts, the altar shall never divulge its secrets except to the darkest of heart and those who are chosen to serve.
You find yourself in a throng of people moving slowly forward. Ahead of you is a figure, deeply hidden in shadow, sitting in a high-backed chair. The line moves forward and each person kneels before the figure, receiving a blessing. With time you move closer to your moment and your anxiety grows -- suddenly you find yourself at the head of the line. A frail hand stretches out to you.
Dressed in a deep hooded robe, you approach the high altar. Cradled gently in your outstretched hands rests a small golden bowl, an offering of holy water for your god. As you slowly climb the dais you are filled with a gentle sense of reverence and peace. Reaching the top step you stumble causing some of the precious liquid to spill out upon your hands. Looking down in horror you see that the bowl was filled not with holy water but with blood. In terror you turn to flee.
Suddenly you find yourself standing on a small balcony overlooking a vast wilderness. You lean for a moment upon the railing for support, a strong northern wind pressing your robes to your skin. The cool air is chilling and invigorates you as your senses feel renewed and keen. Looking out over the horizon your spirit feels as if it is surging with an inner power. From behind you a gentle whisper urges, "All of this can be yours."
A smiling monk places his arm about your shoulder and leads you to a large room where others like him sit at a long table. Smells of freshly baked bread and cooking meats greet you. You suddenly realize that you are very hungry as if you have not eaten in weeks. The monk gestures to a seat on one of the long benches, while another places a plate heaping with food before you. A voice whispers behind you, "Come take your fill. There is plenty here for all."
Thirteen columns representing the dark gods surround the altar.
The pillar is intricately carved with the scenes of a battlefield at the end of the day. The field is littered with shattered armor, weaponry, and broken bodies. The sun is setting low in the evening sky, while a lone vulture sits atop the tallest spire of a nearby castle surveying the destruction below.
The surface of this column has been etched by acid to portray a heart-rending scene. Howling wind and rain blow in through a shattered window of a simple cottage. A young peasant woman wailing in anguish kneels beside an empty crib. In her hands she clutches a small child's blanket stained with blood.
Wearing a weather-stained and filthy gown of once-rich silk, a woman kneels on the side of a well-traveled street. Passersby ignore her plight as they go about their daily lives. One foot bare, the other clad in a broken sandal, the woman cradles a doll in her arms. She pulls back a strand of dirty, tangled hair and comforts the doll as if it were her child.
You tap the Botolf column. - With exacting work, a battlefield scene has been carefully carved into the stone. A valiant band of armor-clad warriors fight what appears to be insurmountable odds in a battle against an overwhelming opponent. Teeth, claws, a mass of flesh, the enemy bears down upon the hopeless little band of courageous defenders who seem determined to fight to the last man. In the foreground a knight clad in battle armor looks fearfully back as he slinks away.
At first glance the smooth surface of this black column appears to have been left untouched. Gazing upon it in the flickering light you begin to notice what appear to be moving shifting shadows dancing upon its surface. The shadows never assume a defined shape, and yet you find yourself reminded of a long-forgotten childhood nightmare.
The column depicts a ship that has broken up in a fierce ocean gale. Sailors and passengers alike find themselves struggling to remain afloat in the violent sea. A wealthy merchant clings to a small piece of debris as he pushes away the grasping hands of a mother and child.
The artist portrays what at first seems to be a pleasant scene but upon closer inspection reveals more. In a quiet wooded glen a small party celebrates the happiness of a young couple's wedding day. Bride and groom look upon one another with the purest of love as they drink a toast to eternal happiness. At the edge of the clearing the best man stands alone admiring the beauty of the young bride, a small vial of poison cupped in his hand.
The carving depicts bolts of lightning streaking across a stormy sky while atop a mountain ledge a Halfling looks down the steep precipice at his Gor'Tog partner below. Heavily burdened by a final sack of gold, the strong 'Tog struggles with the climb. He has but a few moments to realize that his small partner, with seven sacks of gold already at his feet, is slowly cutting the rope with a knife.
In fine detail, the craftsman has depicted a banquet table set in the castle of a baron. A handsome Human man in a tattered cloak sits at the head of the table, surrounded by many beautiful and exotic women wearing crowns and tiaras. The ladies vie for the stranger's attention as a number of pigs root about for scraps on the stone floor.
On the column a fanciful scene has been etched. A young maiden skips daintily through the streets of a small village, laughing gleefully to herself. Behind her follow several men, captivated by her beauty. An angry group of women, brandishing rolling pins and cooking pans, gives chase with wild-eyed jealousy.
Crudely chiseled into the highly polished surface is a surrealistic scene. Blazing high into the night sky, a bonfire sets the stage for a ritual dance. Figures clothed in animal skins, crazily waving swords and spears about their heads, circle the fire in reckless abandon. Partially hidden in the shadows are several pyramids of small skulls -- too large for animals, too delicate for adults, they could only be the skulls of children.
A tiny village sits upon a rise overlooking a bleak barren landscape. A small group of figures go about the solemn task of carrying the lifeless bodies of those who have passed away during the night to a large smoldering fire. Watching, a woman leans against a doorway for support as she stares mournfully upon the procession with the sunken wild eyes of one who knows their fate.
Carved in high relief upon the surface of this column is a humble farmer leading his mule to market laden with the season's work. Six casks of the man's finest ale burden the creature. Gazing up at the clear sky the farmer is unaware that the precious liquid is leaking from fresh holes cut into the casks. In nearby bushes small creatures laugh merrily among themselves, tiny knives in hand.
A seemingly out of place tapestry hangs in the library that reads:
Aena scador vi hoyiro dael,
We prepare an ascending path
Strangely, according to the plaques in the mausoleum, the former inhabitants of the abbey all died at the same time.