Heaven, can you hear me
I am calling from a landline
I need a good connection
I feel like I'm losing my mind
the day is just about to break
I think it's safe to say: so am I
-Lost and Found, Eve 6
A Tether is an area or object that functions as a supernatural link, typically between Earth and either Heaven or Hell. Tethers are major assets in the War, and even the smallest one is considered a significant gain.
Tethers can be attuned to a particular Word on either side, which aside from the matter of possession also influences its effects on the surrounding area. What causes them to manifest is not fully understood, but typically some dramatic event or a particular powerful symbolic bond will do the job. Humanity appears to be able to create Tethers unconsciously; celestials can't, though by causing enough Disturbance in an area, they may keep a proto-Tether from forming.
But though celestials can't create Tethers, they can sometimes guide where they go. When newly formed, most Tethers can be captured by a number of different Words. For instance, the site of a pro-democracy protest could go to Freedom, Factions, Judgment, or any number of others.
Once established, a Tether can be captured or destroyed by the other side, although this is a major play and no easy matter.
A Tether often serves as a base of operations for the side which owns it, acting as a refuge and supply point for allied celestials.