The Hunter's Dream

When you have composed yourself, and allowed the self to become other, then seek out the dream. Enter it not by the wide gate to your doom, but by the narrow. Heed you nothing in the mists, no distractions, no voices, no calls for aid, but stay always upon the path, treading not upon the graves of those who have passed before you. And when you have found the stone for which you seek, cast your message upon it, making clear the one for whom it is written. You must make haste then to leave following your footprints before the blades recover and disguise them from your sight. For the darkness will not stay it's hand forever, and mists hides serpents.

— Teaching of the Hunters Way, Jawsery of Erengyre

Special Tools for a Special Job

Eldritch Hunters are by the very nature of their jobs a solitary breed, but when the natives of your assigned location are clueless about the intricacies of your profession, you need to be able to talk to other professionals like yourself. Unfortunately for Eldritch Hunters, there are very few on each inhabited world, so getting help means, at the least, going to another world, or most likely another plane of existence.
Dimensions being what they are, typical communications would never be able to close the gaps in time and space between Eldritch Hunters. Fortunately, Eldritch Hunters do not have to rely on standard methods of communication.
They have the Hunter's Dream.

What it is

The Hunter's Dream is an asynchronous pull based communications system, and works much like a private message board. The Hunter enters the dream and locates an empty message slot, then addresses the message to the intended recipient who may be an specific individual, a qualified (specialist) group of individuals, or a general request for information or assistance. They then formulate the message and leave the dream. The intended recipients must enter the dream, locate their messages and retrieve them, and may at their option respond to them. Once a Hunter has left the dream, time will flow according to local laws governing gravity and time flow in their home, and the messages will sit in the dream waiting for consumption until their intended recipient reads them. Once a message is delivered, the message fades from active space to the message archive. The persistence of the message is related to the intended distribution of the message - the more intended recipients, the more persistent the message, unless it is removed out of active space to the message archive by the sender.

How it is Experienced

The experience of the Eldritch Hunters as they interact with the dream is fairly uniform. The dream is entered from a state of meditation or contemplation and appears as an area typically representative of the final resting place for the dead of the hunter's native species. The area is covered with some sort of obscuring natural environment from the Hunter's assigned world, and the Hunter is the only person in the area, even if they entered their trance with another Hunter at their side. Messages are left with the dead who can only accept one message at a time. The means of transmission of the message is in a format that is familiar to the Hunter sending the message. The Hunters Dream manages all translation from the sent information to the most appropriate reception means for the receiver.
The communication methodology offered by the Hunters dream can be quite frustrating for the sender as it depends (as all pull systems do) on specific actions on the part of the recipient in order for the message to complete transmission. Despite this, the dream works remarkably well. Messages between Hunters separated by unimaginable distances can be recieved within just a few hours of the transmitter's local time reference frame.

The Why it Works

The Hunter's dream was established by either the Absolutes or by one of the Voices, most likely Sol or possibly the @All as it is a very technical capability that we have reason to believe predates the establishment of the stars. Some traditions hold that the hunters dream was created by ██ ███████ ████████ ███ ███ ████████ ███ ███ ████████ ██████ ██ ██████ ███. The dream works on the basis of the principle of correspondence which states that two pieces of the universe that interact, also correspond to each other, and that what is known by one is inherently known by the other, and can be replicated by it. This is independent of the distance between the pieces or the local time flow where the pieces are.
The Dream is a piece of the universe that corresponds to every other piece of the universe including, apparently, all the different pieces of the universe that exist in the other planes in the universe. The Hunter corresponds themselves through the process of meditation to the Dream, though this is not well understood by many Hunters, who experience the meditation process as "entering" the dream rather than aligning to it, a nuance that is subtle but significant. The Hunter is not able to bring themselves into correspondence with another Hunter which is why the Hunter is always alone. The Psyche of the Dream is somehow connected to the parts of the brain that have mystical experiences, accounting for the persistent themes of death and the chaotic unknown that manifest as part of the Dream. It is not clear if the limitation of alignment is a limitation of the dream itself, or if it is a limitation of the hunter. One the message is conveyed, the Hunter decorresponds themselves themselves from the pieces in the universe that are in the Dream.
Hunters who interact with the Dream confirm that the Dream will not accept things from outside the dream into it, though every Hunter who would discuss the dream with this researcher had tried to do so. Apparently information, as valuable as it is, can be moved, but things cannot. There are varying theories now that postulate the universe as an information network rather than the substance of a material plane, but for practical purposes, the Dream remains a system aligned best to share information.