Glistening in the light of Acheron, the crystalline structure of the Atrium is a fragment of Earth, carried across the void; a snapshot of green and blue amid the pale tans and reds of Tarterus, a promise and a dream.
Under the sewers of a large town ancient burial chambers are discovered. If the PCs investigate they fill find that a pale white flowers grows amongst the graves, in the dark.
How do they survive without light? What is their origin? Why in a burial chamber and not just in any old cave?
Can they be sold or do they have any special quality at all? It is up to the PCs to discover.