The city's carefully managed calm was shattered three days later.
The new form of anomaly did not appear in a quiet alley or a deserted plaza. It manifested at high noon in the Grand Concourse, the busiest transportation hub in Aethelburg.
Thousands of people were planning about, catching trams, meeting friends, going about their day, their minds gently soothed by the Harmonizer network's blanket of placidity.
The illusion of peace made the creature's arrival all the more shocking.
It began with a sound, not a whisper, but a chord of discordant, screaming notes that tore through the air, a sound that was both auditory and psychic.
It was the sound of a thousand voices crying out in pain at once.
Every person in the concourse froze, clutching their heads as the psychic shriek attacking their minds.
The placid hum of the Consensus was ripped apart, replaced by a wave of pure, raw agony, then, in the center of the vast, sunlit hall, the air began to shimmer and distort, like heat haze on a summer road.
The light bent inwards, converging on a single point. The shimmering intensified, coalescing into a form.
It was the birth of an Echo, a creature that the Harmonizers had only theorized about, a Dissonance event that had become so powerful it had achieved a stable, physical form.
The thing that solidified in the middle of the concourse was a nightmare given flesh. It was roughly humanoid in shape, but it had no skin, no features, no stable anatomy.
Its body was a constantly shifting, churning mass of geometric shapes, cubes, spheres, and pyramids that intersected at impossible angles.
The shapes were made of a material that looked like polished obsidian, but they flowed and moved like liquid, and trapped within the shifting crystalline forms like faces in a dark flowing river were hundreds of human faces.
They were contorted in silent screams, their eyes wide with eternal horror, their mouths stretched in agony. They would surface for a moment, their expressions ones of pure torment, before being submerged again into the creature's chaotic geometry.
For a moment, the entire concourse was frozen in stunned horrified silence, then, the panic began.
It was a tidal wave of terror, a mass hysteria that the Harmonizer network was powerless to contain.
People screamed and ran, trampling each other in a desperate stampede to escape. The carefully constructed peace of Aethelburg dissolved into chaos in a matter of seconds.
The Echo took a step. The sound it made was like grinding stone and breaking glass. It paid no attention to the fleeing crowds. It seemed to be driven by a blind, agonizing purpose.
It raised an arm, a limb made of rotating cubes and screaming faces, and swiped at one of the massive marble pillars that supported the concourse roof. The pillar did not crumble or break, where the Echo's hand passed through it, the marble simply ceased to be.
It was not destroyed. It was unmade, leaving a perfectly smooth, curved hole in the solid stone.
Yohan and three other Harmonizers arrived within minutes, pushing their way through the terrified crowds, and the scene was one of utter pandemonium.
The psychic noise was deafening, a storm of fear and pain that made it almost impossible to think.
In the center of it all was the Echo, a vortex of wrongness, methodically erasing parts of the building as if trying to find something, or perhaps just acting out of a blind, painful instinct.
There was no time for subtlety, no time for analysis.
This was not a fray to be tuned.
This was a monster to be fought.
The four Harmonizers formed a line, their minds linking in a desperate, impromptu network. They had to dissolve it, to break its physical form apart and disperse the Dissonance it was made of.
"Focus on its structural integrity!" the senior Harmonizer on the team, a woman named Anya, projected into their minds. "Find the psychic frequency that binds it together and overload it. Now."
They raised their hands in unison, their combined mental force a battering ram of pure will. Yohan focused past the screaming faces, past the churning geometric forms, and tried to find the core of the creature.
He felt it.
A knot of pure, concentrated despair, so potent it felt like a black hole in the psychic spectrum. It was the source of the creature's power, the engine of its existence.
They poured their energy into that knot, projecting a counter frequency, a wave of pure order and stability.
The Echo reeled back, letting out another silent, psychic scream. The faces within it contorted further, their agony intensifying.
The creature was fighting back.
It turned its attention from the pillar to the Harmonizers, and the full force of its despair washed over them. It was a feeling of utter hopelessness, of being lost in an infinite, cold void, abandoned and forgotten.
It was a psychic poison designed to break their will, to make them give up.
One of the younger Harmonizers cried out and fell to his knees, his concentration shattered. The psychic backlash hit him like a physical blow. The remaining three, Yohan, Anya, and another man, held firm, their mental shields cracking under the strain.
They had to end this now.
"All at once!" Anya commanded. "On my mark!"
They gathered every last ounce of their strength, their love for the city, their belief in order, their own desperate fear, and focused it into a single, lance like projection of will.
On Anya's mental signal, they unleashed it.
The lance of pure psychic energy struck the Echo's core. For a moment, the creature seemed to absorb it, its dark form glowing with a terrible inner light.
The screaming faces became clearer, their expressions turning from agony to a kind of pleading.
Then, with a final, deafening shriek that shattered every window in the concourse, the Echo imploded.
The shapes flew apart. The screaming faces dissolved into mist. The entire creature evaporated into a cloud of black, glittering dust that quickly dispersed, leaving nothing behind.
The concourse was silent again, save for the distant sirens, the moans of the injured, and the sound of Yohan's own ragged breathing.
He stood, swaying on his feet, utterly drained.
They had done it.
They had destroyed it.
But the cost was immense.
Dozens of people were injured in the stampede. The concourse was damaged, with strange, perfectly smooth holes carved into its walls and pillars, and the city's illusion of safety was irrevocably broken.
Everyone who had been there had seen the monster. They had seen the impossible. No amount of psychic soothing could erase that memory.
The war was no longer a secret, fought in the shadows by Harmonizers. It had just spilled out into the open, in the busiest part of the city, in the middle of the day.
The Echo was a declaration. The sickness was no longer content to whisper in the dark. It was now screaming in the light.