The Waters/ The Stem

Accessible via death (for all but Alarë?), the waters is where the dead travel to their final destination via ships. An Aboleth rules over this domain, 'taking' the dead while itself remains "immutable". The journey into the waters from life has been via a Plunge Pool Cavern, which carry the dying through a Sphincter of four connected quadrants, who then surface to an endless ocean.
In the Leaf analogy (where The Waking is the topside of the leaf and The Dreabig is the underside), the waters is the stem that carries souls to The Tree.
The connection between the waters and the Tree is blocked, or plugged, meaning the ships meander the waters, unable to find harbour. This has resulted in the dead becoming faceless, featureless, memoryless. Sigrid has been tasked to remove The Plug from the reality side of the leaf.
After Qwyn blew a hole through the sphincter that accesses the Waters in the first attempt to res Oksana Bosko, Reika Günay was tasked by Father to fix the slight leaks at the bottom of the ocean.
While Oksana Bosko waited on the ship, The Boy / Koschei disintegrated, not belonging in that realm. Oksana managed to hold onto a piece of him.
During the 3rd (successful) attempt to resurrect Oksana, Oksana let go of this piece of the Boy. In leaving the afterlife with both Oksana and Moonlight Through Rain, Qwyn broke through a barrier on top of the ocean and saw The Tree before ending their Spirit Walk.
This second breaking opened a great chasm and drained the ocean. Ships burned, dead vanished into The Void while some seeped into a world of shadow and unrest and hate. With the passageway from The Tree to The Waking broken, no new life will come into our world.
Aboleth/Father's guesswork solution to fix this was to bring back all the shadowed souls and maybe then we can sort something out.
Until then, the Probably Fine status has officially been upgraded to Totally Fucked.