The Mysteries is a catch-all term for those who worship some divine entity other than the realms. The largest of these are the followers of the Deep: a great source of power believed to reside at Althane’s core. Others worship the cycle itself, powerful planar entities, or (in rarer cases) entire pantheons unrelated to the realms. While any individual case of worship in the Mysteries is small, the sheer quantity of variations on the theme means that close to 20% of devout people on Althane fall into this category.