Mattermead had selected Pauper Ponds as the location for the ritual that would see poor Nora restored to her prior form. The area had a potent arcane footprint from which Chao Maleficarum could draw power for the ritual and, more importantly, plenty of open space for public spectacle. No feature of the ponds contributed in any way towards enhancing the physical security of the ritual - parties could come and go with little to no challenge.
The reagents were distributed to magi who had been charged with implementing a subset of the wards that would be necessary for the ritual. Runes of power were marked on the ground in exotic and highly volatile inks, configured to create fields of magic useful for transmutative manipulation. Again Mattermead would orchestrate the many mechanisms that culminated in the ritual's entirety.
There was an air of apprehension among the crowd of magi, spectators and the few who were indeed present to prevent interference from attendees. Mattermead Gold signaled the beginning of the ritual with his effeminate hands and promptly the stronger arcanists among Chao Maleficarum's number began chanting words of power in tandem with the somatic gestures of their hands. Their combined channeling began to fuel the mechanisms of the ritual, activating the various wards and fields. Nora stood ensnared by a spiral of potent glyphs just east of the ritual's central locus; it is difficult to read a bugbear's snot-covered, savage, furrowed face, but one might have guessed at seeing a mixture of anxiety and hope in its black, beady eyes.
The energies of the ritual visibly ebbed and flowed, bathing the eager spectators in gentle multi-colored lights. Here and there one could see small tears forming in the fabric of reality from the use of wizardly powers; a small team of sorcerous conjurers ran from seam to seam, sealing them as quickly as they formed.
Mattermead conducted quite expertly, making small corrections and redirecting the eddying powers. The transmuters, attentive to Mattermead's subtle gestures, focused their attentions upon Nora, words of mutable power flowing from their lips. The monstrous bugbear's form began to obscure, stretching into unreality.
Mattermead smirked; everything was going to plan. Soon ring 99 would be singing the praises of his wizardly prowess.
Nobody saw the scoundrel in time. The retainer of a noble house of dubious origins, his heart was filled with discord and had no room for outmoded sentiments such as altruism. This day he craved to make a mess of the lives of others, so that they might taste the chaos that was his own life. Unchallenged by the absence of physical security he approached a reagent key to warding against the powers of contagion and took it, removing it from the mechanisms of the ritual. His action was noticed, but too late. The perpetrator drank a vial of retreat and was gone. The damage had been done.
Energies of sickness and disease began to infest the ritual ever so slowly. Gradually, gradually they gained purchase. Henceforth their propagation accelerated beyond reasonable expectation.
The mages of Chao Maleficarum struggled to regain control. Sweat beaded Mattermead's face as he grappled with the myriad of intruding arcane threads. There was little he could do, even the most capable of sorcerers would be powerless in the face of such unfathomable variation.
Nora's form began to anchor again in the material world. To look upon her just minutes prior one would see naught but a gestalt that avoided the direct observation of the eye, portraying instead infinite possibility. Now one could see the outline of being, of reality resolving.
The maelstrom of energies about Nora culminated, giving off a sickly green light. It grew brighter and brighter, blinding all spectators.
Mattermead had lost control. He did not know what to expect. In a final bid to capitalize on the possibility of success he announced victory to the assembled, heralding the salvation of Nora. He signaled the end of the ritual. The channeling stopped.
When the blinding light faded, there stood in their midst a being most foul; an elemental of the seam of contagion, of bile and pus. Nora. Its stench turned the stomachs of all present, forcing them to evacuate their contents entire.
Mattermead turned a shade of green, and not only because he'd just vomited in public. He knew that this result was the end of Chao Maleficarum, and an even greater blow to his reputation. How could he possibly hope to recover?
And then arbiters began to stream out from the surroundings, violently overwhelming the little physical security that was present to protect the ritual. Blood was spilled with savage efficiency.
Nora's form liquefied and became rivulets of pus and bile that flowed into the water of the ponds, securing escape.