By Dennis Detwiller, © 2012
Fighting the forces of the Cthulhu Mythos is one thing, confronting the roiling insanity that is Carcosa is another. The otherworldly madness and horror the Old Ones spread is due to their impossible nature and unknowable methods. Carcosa, the horrific realm of Hastur the Unspeakable appears different, but may simply be another manifestation of this impossibility.
Few Agents can feature the differences between an inhuman monstrosity loping at them from the sea, and a house that seems to bend and warp around them, changing as they observe it. One seems separate from humanity, a monster, the other seems to warp and change the deepest and most coveted concepts of humanity — thought, ideas, order.
Carcosa is a name given to the slurry of thought and quantum possibility that exists between man and the Great Old Ones. In this run off, human thought is pulled into a void and fills the space of possibility with thoughts, dreams and ideas. The collapse of the waveform becomes the dance of multiple waveforms — a thousand outcomes become possible, or impossible at once.
This effect occurs in a limited manner in so called “non-euclidean” constructions. The warping of space/time evident in some structures left behind by the Old Ones exhibit a bizarre change in human perception. This seems to be a fixed effect — the perception is shifted depending on location, but rarely seems to “bleed” or “change”, instead, it looks alien and surreal.
Carcosa, however could be more akin to a feedback loop in this area of “reality”, a tug of war between an infinite consciousness considering a finite reality, and a human consciousness observing the same. Carcosa seems to act and react to human thought, to change and direct itself in a within human concepts of fear and disorder and chaos. As such, it is extremely potent in its effects on sanity.
Attempts to understand Carcosa always fail. Carcosa may appear to become “ordered” for short periods based on Agents’ mental fortitude, but this is always a momentary pause in a dance of horrors that swarm the mind. It is like an undertow in the current of thought, deceptive at first — appearing subtle and easy to resist — but soon, as the Agent is pulled out to sea, the truth is realized. Carcosa envelops and digests humans like a slug, ingesting and burning away their minds. All that remains behind are their thoughts and perceptions, which sometimes echo in the slurry forever.