'I was told that everyone I'd served with in the military died shortly after I left.'
The Ink is a zone of zero electromagnetic radiation, several miles wide, first encountered on [[Earth 44]. Characterized by the observable effect of blocking or absorbing all visible light, this phenomenon can only be illuminated to the range of approximately 10 feet from the source of radiation. As the phenomenon also affects radio, the only way to communicate further than this range is via overlapping relay stations less than 10 feet apart. UAV flights would lose contact when travelling through The Ink, but would eventually emerge from the other side having recorded nothing visible.
While it is unknown how The Ink is maintained or created, the Earth 44 version of it contained a range of dangerous entities, including a large reflective mirror-like creature known as a Mirror Octopus, described by Higgins as being similar to a gigantic snake or tentacle. As well as the mirrored creature, The Ink also appears to be inhabited by intelligent, malicious creatures (Animal Shadows) who deliberately taunted Higgins by placing dismembered remains of his squad mates in his path while he was attempting to escape.
The Ink appears to be generated by the Shadow Sphere located at the center of the phenomenon. The exact nature of the Shadow Sphere is largely unknown, however it appears to act in a way similar to a Portal, connecting to the worst realities encountered in the multiverse. This is the source of the other entities present in The Ink, which wandered or escaped through the other protrusions of the Shadow Sphere in their own realities. The sphere itself is a projection of the reality on which The Hunger and its related Shadow Entities exist.
Blocks all electromagnetic radiation beyond a range of 10 feet from its originating source. Extends across a range of miles and can be inhabited by a variety of mostly unknown but hostile creatures, such as (at one point) the Preacher, as well as Animal Shadows.