On a large, mesa-like area, fairly desolate and isolated lies an abandoned monastery (kojani pagoda complex?).  Various low level undead types have been coming from the direction of the complex and harassing a local village.  When the players arrive, they are directed to speak with the village elder about the situation.

The village elder relates that the monks seemed to have just vanished one day, and several years later, undead were seen in the area.  Only recently have they been venturing as far as the village.  The elder gives the players a page from a diary of one of the monks found on an undead soldier.  The page is obviously part of a much larger dialog, as it is a fragment of a larger thought, and it reads something like…

            ‘I feel Brother Bogart is disturbed.  He is not himself of late, and has taken to regular absence from prayer.  Many times he can be seen exiting from the catacombs, and he does not look well.  He is sometimes heard laughing late at night, and he has been caught twice already trying to take one of the sacred monument jewels.  Some feel he took the one that is missing and has placed it deep in the catacombs for some unknown purpose.  Many here have been having dark dreams and become uneasy with the daily goings on here.’

The village elder should mention that the situation in the area has been getting progressively worse since the undead invasion of Thestra, the monastery had been abandoned and quiet, it’s no longer safe to travel in the area, etc.

Players then venture to the monastery, finding that once they get to the base of the mesa-like area, they must climb narrow stairs and fight undead on the way up, avoiding falling.  At the top, there is a complex of buildings which the players must search, defeating creatures and undead, until they find the key to the chapel and library in the abbots chambers (perhaps defeating a ghostly abbot to obtain the keys).  With the key they find another, earlier page of the diary that describes Brother Bogart’s vigor at discovering a new type of meditation from some old manuscripts in the library, and how much closer to enlightenment he gets using this new method.

Using the key to the library (the chapel is magically sealed as well as locked) – the players must clear out undead and find the old manuscripts used by Brother Bogart.  The manuscripts lay out, in some detail, a meditation for contacting beings of another plane.  It can be seen that the texts were revised to show that specifically beings of another plane has replaced beings of a higher plane, and in a different handwriting style.  Also in the scripts is the phrase needed to unlock the magical seal on the chapel.

Once inside the chapel, players encounter more and more difficult undead, culminating in a battle with a tough group boss, perhaps the chant master or assistant abbot.  Defeating this creature gives access to the catacombs through an antechamber that is near the door to the chapel graveyard.  The graveyard contains a one way door that leads out of the catacombs – players cannot enter through it.

The catacombs of the monastery proper aren’t all that large, complex or amazing – mostly storage areas, a few roaming undead, and a few penitents chambers (sort of like a dungeon cell, only without the doors that lock from the outside only).  One of those chambers has a barrel blocking a low tunnel.  Moving/destroying the barrel (which is trapped) gives access to the tunnel.  Players must crouch to go through, and it leads in a spiral down, ending in a short chute drop (making it one-way going in).  At this point it starts to get more interesting.  All the walls, floors and ceilings are rough hewn.  Lots more undead.  The most interesting part is the layout – rooms are evenly spaced, diametrically opposed to other rooms, making each room a point on the surface of a sphere.  The connecting corridors lead in a spiral pattern from top to bottom, so you go round, then just before you get back to the room where you started, it dips underneath, and you go into another circle, then dip down, and so on, each circle getting wider until you get to the circumference of the sphere, then it starts getting smaller again.  There are undead and dungeon-dwellers wandering about, with minor bosses in a few rooms.  There may be some short branches of tunnels and rooms leading away from the sphere, but never into the middle.

Here is the lynch pin – in 6 of the rooms that are all on the same plane (either horizontal or vertical.  Horizontal being easier, vertical being much cooler) there is a large receptacle and two holes in the wall pointing inward (looking through them is nothing but blackness, and they are too small to climb through).  The end result is that if you drew a line between each receptacle based on the direction of the hole, and connected each room along the plane; you end up with a 6 pointed pentagram.  At various points along the spiral down, there are mini-bosses.  Each boss has a large gem of a different color (white, red, green, blue, yellow, orange) and a portion of the diary.  The diary details the descent of Brother Bogart into madness, the sacred monument jewels and their disappearance. Finally, there is the last boss, who has the last pages of the diary, which are written by Brother Bogart.  They describe how he used the sacred monument jewels, which are actually demonic reliquaries that the monastery was ordained to protect – over time, it was forgotten why they were protected; they were merely religious artifacts to the monks.  Brother Bogart, in his new meditations, was contacted by a demon, and deceived into believing the jewels held trapped benevolent souls – that the jewels were reliquaries used by demons to trap the souls of the good who fought against them, eventually falling into the hands of the monks, who sought to protect the jewels from being used for evil, and allowing the souls of the good to rest.  This demon convinced Brother Bogart that he needed to perform a ritual to release the souls and destroy the jewels to return the lives of those taken by the demons.  So Brother Bogart listened, followed the demons’ instructions, and created the Sphere of Chambers under the monastery, using rites and rituals the demon instructed him in to raise undead (deceased buried at the monestary) to perform the labors and defend the work.  Once completed, the demon instructed Brother Bogart on how to place the jewel reliquaries in the receptacles of the rooms in the sphere – once placed, each jewel shone a beam (of the color of the gem placed in that receptacle) out one of the holes in the wall to touch one of the other receptacles.  By placing the jewels in a specific color pattern, it would unlock the jewels and free the souls.  This was, of course, a lie, and when Brother Bogart placed the jewels, it unlocked the trapped demons, which then slew the monks of the monastery and devastated the local countryside.  While this was happening, Brother Bogart was instructed to change the order of the jewels to unlock the prison the demon was being held in.  Still convinced that he was working for good, Brother Bogart began to comply, but was stopped by the last monk left living (the one who wrote the initial part of the diary).  Defeated, Brother Bogart escaped, found the diary of the monk who had stopped him, and in a fit of rage, destroyed the book.  Only after this did Brother Bogart realize his transgression, and finish the diary with instructions on how to arrange the jewels to open the prison of the demon that had deceived him.  Brother Bogart then returned to the Sphere of Chambers, collected the jewels and attempted to escape, only to be found by the last remaining monk and killed in a second battle.  Weakened, this last remaining monk fell to the undead before he could undo Brother Bogart’s work, and the undead took the jewels when they disposed of the monks’ bodies.

Once the players have all the jewels and the instructions, they place the jeweled reliquaries according to the instructions, and the center of the chamber of spheres becomes available (through a door that appears once everything is in place).  If the six-pointed pentagram is horizontal, an elevator down from the top or up from the bottom, if it is vertical, a platform that moves from the edge to the center).  The center area of the Sphere of Chambers is black, or near to it, with the six colored beams forming the pattern.  Once the players reach the center, they enter a different room, wherein they battle the demon.

This demon is Ahg-zhum, a shadow demon.  He is big, horned, and really ugly.  Black skin, lots of horned points, vaguely dragon-like.  The room starts off heavily shrouded in black fog.  As the battle progresses and Ahg-zhum takes damage, the fog gets lighter and lighter, and the light in the spatial room gets brighter and brighter.  Once Ahg-zhum is defeated, the room is bathed in bright white light, and the jewel reliquaries are destroyed.  The ghost of Brother Bogart appears to thank the players for defeating the demon and freeing his soul, and he highlights the stairway out of the chamber.  After the players finish in the spatial room, they take the stairs out (which exit at the one way door in the graveyard mentioned earlier).  If Ahg-zhum is unlocked and the player is a member of the group/raid that unlocked him, then the one way door from the graveyard may be open to allow them to enter quickly for looting and corpse recovery or further shots at defeating him without having to repeat the dungeon to find the jewel reliquaries.

This final encounter could be used as a flag for further quests in a branch, perhaps to find the 6 demons (one of each of the jewel colors) released from the reliquaries – in which case Brother Bogart’s ghost could point the players in the direction of the next leg of the quest.