When one is pursuing an understanding of things which manipulate fundamental forces and universal laws, the unintended side effects can sometimes exact too steep a price.
A great many of the rarer sicknesses and syndromes that confound medical science are, or come about as, a direct result of exposure to the things that most people will never know to exist: There are poisons and potions that burn and transform, venoms and toxins whose workings are even more painful than they are inexplicable, and rites and rituals that can kill their intended targets as easily as they might otherwise have weakened or wounded them. Other maladies can have a less obvious aetiology, and might represent the cumulative effect of repeated experiences and encounters; as can be the case when recurrent interactions with unimaginable horrors compound and fester into the acute onset of various, and variously debilitating, mental illnesses, or when a lifetime working in around certain environmental hazards increases the likelihood of related cancers.
Of these more subtle sicknesses, perhaps the strangest of those to which I can speak of with the most direct knowledge (albeit second-hand) is Delirium Tempus; a condition that is believed to be caused by regular or routine interaction with creatures, objects and phenomena that can affect or influence the typical flow and passage of time, either wilfully or simply by their presence. Prolonged or repeated engagement with - or exposure to - various of these or (potentially more dangerously) a variety of these, can lead to someone becoming psychologically unmoored. Trapped within a tumultuous tempest of sense memories from various other points in their lives - both from their pasts and, it is strongly and generally believed, their futures - sufferers of Delirium Tempus experiencing them in a perfect and almost paralysing psychic simulacrum.
Some have argued that Delirium Tempus represents a previously undiscovered form of atemporal quantum entanglement, the brain of the present physically forced and chemically compelled to become a copy of itself at another point along its own timeline. The best available evidence might even support this, pointing to a neurological inconstance of fluctuating physiological changes in the brains of those experiencing Delirium Tempus. Nonetheless, and without comparative data about those same brains at the points that are being relived - or pre-lived - this theory will remain only a convenient conjecture from which to assay our best guesses. Perhaps its greatest strength is as a deliberate sop to those who can accept the unexplained, those discoveries whose place within a theoretical complete understanding of our world is only as-yet unknown, but who balk at the idea of the fundamentally inexplicable.
In its early stages, Delirium Tempus can present as frequent but intermittent bouts of apparent déjà vu, either action then memory or memory and then action - with such a minor temporal variance between someone’s present and the moment they are experiencing that the two are functionally identical. Although the progression from this first symptom to more severe and debilitating forms of the condition can take several years, Delirium Tempus is always, inevitably, degenerative. The worsening of the symptoms is presaged by dreams (or nightmares, depending on their content) - memories of both what’s past and what’s yet-to-be from points much further from the present than were shown in the presumed déjà vu. Interspersed with more common oneiric fare, and as easily and often forgotten, they nonetheless rob the sufferer of more fitful rest; unfortunately, the least of the coming issues.
What follows are vivid and intrusive flashes of memories, which can be interpreted as visions or fantasies when they show someone’s future, accompanied by some degree of petit mal seizure. Bodily present and apparently physically unaffected by the content of the memory - the mind does not, in the case of Delirium Tempus at least, manifest any perceived harm onto the body - these seizures will typically only last a few seconds at this stage in the condition’s progression. Unless the sufferer is in the midst of a physical interaction or in the middle of a sentence their momentary absences might go unnoticed, even to themselves, until the episodes become longer and more pronounced. Often mistaken for another seizure disorder, those diagnoses are revised when they cease, abruptly, and the condition reaches its final stage.
Seizures had previously marked the distinction between the points at which the mind and body were temporally aligned and those when they were riven - perhaps were even a sign of the mind resisting such separations. Afterwards, Delirium Tempus more closely resembles advanced dementia; the physical and psychological experiences becoming entirely untethered and only occasionally coming into fleeting concert. No longer frozen in recollections, a new balance is made - with varying degrees of success - as the person with the condition exists both alongside and at an ever-shifting degree of remove from those around them. Their thoughts and actions may seem to be random - they are seldom contemporaneous to the circumstances as presented to those still walking a single, linear path - but if we could pair them with the correct point in that person’s life, they would make perfect sense.
Prophecy, inasmuch as genuine examples exist among the morass of guesswork, fabrication and self-serving pronouncement, may find its origins in cases of Delirium Tempus. Naturally they would be limited to events within the lifetime of the prophet in question, but those of a mind and of a suitable inclination and temperament have been known to seek out those in the chronic final stage of Delirium Tempus, hoping to find a diamond in the screed of contextless outpourings. Nonetheless, such supplicants could provide clues as to the malleability and mutability of the future, if they were reliably able to properly interpret the utterances and actions of those with the condition and divine something certain and meaningful and attempt to stop - or fail to stop - these foretellings from coming to pass.
Knowing how catastrophic the accumulation of exposure to atemporal phenomena is, most who are aware that such things might even exist tend to approach their study cautiously, if at all. Unfortunately, many of the minor instances are difficult to discern - our imperfect perception of time allows us to gain or lose seconds or minutes, sometimes hours, without even noticing - and the causes of such occurrences are seemingly more numerous than had previously been assumed. Some, braver or more reckless than most, are trying to map out just these phenomena. It is a thankless task with a potentially grim reward at its end, and is often frustrated by the transience of temporal slippages, loops and unexplained accelerations and slow-downs. However, since there are no effective treatments for Delirium Tempus, limiting the number of potential cases seems to be the only meaningful course of action.