The Istós, also referred to as the “the Loom”, is "the is the world-behind-the-world, the realm of energies that bind life and matter together. It often appears to those who can see it as a vast web of strings that occasional bind together into a knot, called a Desmós, to create life. There are occasional wisps and motes that dance around the strings that appear to be composed of the same ‘stuff’ of the Istós. There are innumerable phenomena that scholars are still recording.
Above all, the Istós is the energy source and catalyst of Tuning in the world. Tuners use several different means to apprehend and manipulate the Istós. Very few have a natural grasp of the Istós, and most spend decades trying to even glimpse it.