In the mountains north of Guran, there stands an obelisk of dark metal with a surface as iridescent as a beetle's shell. While difficult to reach, as no trails last for long in the region due to a combination of violent storms and the effects of the obelisk itself, it can easily be detected from nearly half a day's journey away, as the entire landscape gently trembles.
Up close, the structure visibly vibrates at a continual rate, the motion trembling through the rocky structure of the Black Riage like ripples on a still lake. Over time, these vibrations are wearing down the mountain range within 16 kilometers or so of the obelisk, causing carved paths to crumble and sending avalanches tumbling down the slopes.
Those who have braved the hazards of the region to study the structure claim that it is ever so slowly working itself downward into the mountains, at the ponderously slow speed of a millimeter or two a year. What the obelisk is digging toward, if indeed it digs toward anything at all, is a mystery. Some think that it serves to ward some other threat from the location, and would pay handsomely for any proof that the shivering obelisk is some manner of marker or defense for something the ancients buried beneath the Black Riage.
Seeds for the Shivering Obelisk:
The people of Guran are getting concerned at the increasing frequency of earthquakes affecting their settlement, and as such are offering a reward of a handful of oddities, cyphers, and even an artifact to anyone brave enough to seek out the cause of these events. Investigation leads adventurers to the Shiver Obelisk, whose descent into the earth has reached an previously unknown faultline that extends south to near the edge of Guran. It may be possible to shore up this fault, but the risk exists of releasing all the pressure along it at once, which would devastate the town and kill many innocent people.
Reports of strange lights in the vicinity draw the group to the Obelisk, where a strange religious group has gathered to pay homage to the structure, which they see as a manifestation of their deity, the Trembling One. They'd be harmless enough if it weren't for the fact that they feel that the Obelisk must be appeased with a living sacrifice, and none of them want to volunteer since the Trembling One's promised afterlife is less than pleasant.
Storms gather over the Shivering Obelisk more frequently than anywhere else in the Black Riage, unleashing torrential rains and heavy lightning; the former sweeps away any attempts to carve safe paths to the site, while the later seems to be drawn into the Obelisk itself. An enterprising scholar wants someone on site during a storm, based on a half-rotted report of a maddened explorer who claimed the structure opened like a flower during one storm, drinking in the lightning with delicate-seeming petals.