The party was condemned by the Mad Sultan to be entombed with the deceased blood prince as his Death Slaves of Eternity, to follow him into the after-life and be his servants forever. The prince was foully poised while visiting the inn some of the various characters were staying at, while others were rounded up and condemned for being among the last to see him alive after he transacted some business with them (asking the blacksmith what he might know of a chunk of a strange green alloy in the prince's possession; asking the herbalist for herbs that would relax the body and induce sleep, asking the jeweler to fashion a silver mask in the shape of a skull, asking the astrologer about a strange chart of alien constellations). The PCs had heard rumors of the crypts, including that the Mad Sultan's first wife died mysteriously sixty years ago and her two young children and the court physician were declared Death Slaves and buried with her, that the Gates of Paradise are hidden somewhere down there, promising immortality for all who enter, that a squad of royal guards had entered the crypts a week ago and never returned, that an ancient and haunted monastery of a death cult lies long abandoned somewhere below, and that Xothula, the last great god-king and ancient ancestor of the Mad Sultan was never a god-king at all, the true god-king was murdered and buried in the crypts.
The prince's body, wrapped in a ceremonial shroud and placed on a bier, was lowered on a copper platform down into the depths of the catacombs, along with guards and the Death Slaves. The guards moved the bier off into the corner and others herded the party off the platform, which swiftly rose back into the darkness. They had been lowered into the middle of a huge rotunda, with the peak of the ceiling over 50' up, that was lined with odd red tiles, from which stuck fist-sized glowing green rocks at random intervals providing a gloomy illumination. The party was in the middle of gathering up the various grave goods (including their own possessions as well as bread and wine), when they were attacked out of the darkness by a group of ragged figures in hooded cloaks with skull for faces; strangely the figures concentrated on snatching the edibles rather than hurting any of the newly arrived Death Slaves, and the party was able to fend them off, slaying one in the process. At that point the attackers who were led by a giant of a man in a leather apron and executioner's hood, revealed they were also Death Slaves, and they had just been trying to snatch up all the provisions they could before the "Children of the Grave" showed up.
At this point a howling pack of grossly deformed child-sized humanoids surged out of the shadows and began tearing and biting at the various NPC Death Slaves who were standing around dithering. A light flared down a hidden tunnel, and the fake ghouls retreated swiftly down the tunnel, with our "heroes" in close pursuit; at the end of the tunnel the slaves and the huge man, Babatunda, jockeyed an enormous marble table into position, sealing off the tunnel from the Children of the Grave.
The room they retreated into turned out to be a huge temple, with red tile, marble floor, giant pillars, dominated at one end by the statue of an enormous man made from some unknown green alloy, with its hands outstretched, palms empty in a gesture of peace; the head of the statue had been hacked off, leaving jagged edges.
In the monastery the group found dozens of pale and sickly looking wretches, being tended to by an old man with a long white beard and blind in one (milky white) eye. He called himself the physician and welcomed them to his flock, offering them stale water and dried sticks of meat, which was all they had to subsist on; when questioned he revealed that the food and water came as a result of his prayers to the gods. When some of the party wanted to learn how to do that he told them he'd be happy to teach them if they took up the faith, but that would involve months or years of study… plus they needed to be literate, which none of them were.
Closer examination of the statue showed long stretches on the back of the statue similarly hacked, where the man's wings would have been (assuming it was some sort of angelic figure). The green alloy was harder than the steel of the jeweler's chisel, which couldn't so much as scratch it.
After interrogating the Physician further, poking around trying to follow Babatunda, and generally agitating his flock with questions they uncovered the rumor that he was the very same court physician who was the first of the modern Death Slaves, had actually murdered the sultan's wife, which is why he was condemned. Babatunda had been with him that whole time.
The Physician offered to give them a map which might lead to an exit through the Crypt of the Faithful, that he had assembled from the ancient writings that he had available, but was probably dangerous and certainly more rigorous a journey than his flock, some of whom were too weak to even walk on their own, could possibly make. Still, the group seemed hearty and if they wanted to chance it, they could have the map with his blessing.