Instantaneous communication over vast distances has always been a goal of human endeavour (both magical and technological) though the efforts and results have been mixed.
A primitive, powerful and sometimes dangerous attempt to create a technology that would allow for instantaneous communication over long distances, what little we know about the provenances of Sublimation Halos suggest a collective, even international effort at odds with the prevailing culture and climate of the day. Evocatively and nebulously ancient in appearance, they are translucent blue crystalline crescents half a centimetre thick and inlayed with shallow grooves cutting square patterns across the upper and lower surfaces: Even inert, more art than artefact, they are immediately striking, and arrestingly dangerous. A mixture of circuitry and guttering, aspects of their design seem drawn from the remnants and relics from cultures as distinct and disparate as those uncovered in the archaeological sites of Mesopotamia and ancient Egypt and Jiǎhú.
Sublimation Halo’s could not have been the result of an intentional such collaboration (a prospect rendered impossible by the vast and unassailable gulfs in distance and time) but they are perhaps a culmination of ideas and efforts originally made long before they would eventually be realised. A fumbling and uncertain continuation of imaginings and ingenuities that had previously overreached and outstripped the advances needed to see them through to fruition, we can hardly fathom the nervousness and excitement with which their prototypes - their workings perhaps only slightly better understood then than now - must have been created. Originally a pair, by necessity (like Bell’s telephones), we do not know if their first users were volunteers or, as seems more likely, unwitting and unwilling test subjects.
From more contemporary descriptions of their use, we know that they were placed on the freshly-shaven heads of their intended recipients at a forty-five-degree angle, cutting up the cheek and over the ear. Activated with a short and precise series of haptic inputs, they pulsed with uneven, irregular bursts of golden-hot light that arced around their outer edge and through their carved pathways. Next came the heat, an immediate and intense flare of physical and spiritual agonies that fused and hard-wired the prostheses into flesh and bone and deeper, into mind and soul: A life-long and irreversible bond. The pain of the mutilation would have been as overwhelming as it was abrupt, a sacrifice that shocked the Sublimation Halos’ wearers into a deep (and brief) but necessary unconsciousness.
In this dreamless sleep their central nervous systems were able to begin to adjust to - and integrate with - the presence and functions of the Sublimation Halos. This process, a mixture of healing any damage caused by the fusion and growing brand new connective tissues, was far faster than nature alone would allow for. The external signs of trauma had, for instance, scabbed over and then scarred in less an hour, with the subjects regaining consciousness not long thereafter. All the pain was gone, the unfamiliar and not-insignificant weight of the Sublimation Halos being the only discomfort remaining. Even this was offset by the anticipation of their new abilities though, abilities that proved surprisingly easy to control, and of which fine control had apparently (as with their healing) been similarly accelerated.
Whilst they initially had to speak aloud in order to transmit messages between the Sublimation Halos (the recipient hearing the message as if they were in the same room, no matter the actual distance by which they were separated) they were soon able to pass unspoken thoughts back and forth, almost conversational in pace and ease. This progress took only hours and the next steps, sharing images and then more abstract messages, were achieved within days. Soon, the only outward sign that Sublimation Halos were anything other than some unwieldy decorative headpieces were pulses and strobes of light coursing back and forth within their translucent crystal surfaces; an uneven, staccato flow marking the passage of information back and forth across an incorporeal, uncertain and immeasurable medium.
Beyond and besides the immediate and obvious drawbacks of the Sublimation Halos (despite continued and concerted efforts across the centuries between their creation and their fall into obscurity, neither their obtrusive dimensions nor the painful permanence of the bonding process were meaningfully or markedly refined) their use incurred another, more insidious penalty. Whilst their ability to share information flawlessly between their users was unparalleled - and perhaps remains so even to this day - they also created the risk of informational bleed: intrusive flashes of thoughts and imagery that arrived unbidden and without a definite source or sender. The explanations for this bleed are necessarily speculative, given the uncertainty around the Sublimation Halos’ origins and physical construction, but some have argued that the flaw offers potential clues to their underlying architecture.
Whilst most of the unintended and unwelcome signals that comprise the bleed have appeared to be little more than white noise - though some have theorised that this was information that was so densely compressed and crowded as to be undecipherable and incomprehensible - other elements have been understood, unpicked or unpacked. These intelligible fragments, more identifiable by their very nature, have been used to demonstrate that at least some of the data imparted by information bleed originates outside that which would be available or accessible to the contemporaneous network of Sublimation Halos users. This suggests that the medium of transfer is an extant, intrinsic field and was not created by (or uniquely accessible to) a single human technology: We might even take it as evidence of a collective consciousness.
There are indications that the interference only grew more pronounced and problematic as the number of Halos in use, or having been used, increased over time. This though, does little to indicate if the problem is the exponentially increasing complexity of the Noosphere (a term sometimes taken as analogous to the idea of the collective consciousness) or was the result of the cross-contamination of echoes; every deliberate or stray thought shared via Sublimation Halo having left an indelible mark on the medium of their transmission. Regardless, and although the loss may have cost the world a potentially useful avenue for studying aspects of various psychic phenomena and their associated mechanisms, the prohibitive cost and difficulty of constructing new Halos seems to have more definitive in their eventual abandonment.
More than a thousand years have passed since the heyday of Sublimation Halos, their last recorded use coming before the Black Death cut its grim path across Europe. They fell out of favour relatively quickly, soon becoming too obscure even for legend, which has led some researchers to theorise (almost entirely without basis) that their elimination was part of measures to help hide the invention and distribution of a more refined version of the technology that could be employed for spying and subterfuge. No examples of such advances are known to have been discovered however and, even with the advantage of surviving pieces of Sublimation Halos and the remains of some bonded users, the best attempts to recreate working examples have met with continued failures and frustrations.