In a ruined world where the Rumbling was never stopped and the rest of humanity lies crushed beneath endless stone, the last survivors on Paradis claw at a fragile existence under the shadow of genocide. The Jaegerists rule with Queen Historia at their head, Zeke and Floch enforcing a peace built on fear, while Armin and Jean’s Alliance survives as a bitter, exhausted resistance despised by the very citizens they once swore to protect. Into this uneasy stalemate crawls a new horror, born from melted glaciers and an ancient microorganism akin to the one that once twisted Ymir’s fate, now taking root in the body of a blond tabby warrior named Reiner.

This book follows the Alliance from the moment Reiner pads back from the sea unknowingly infected, to the night Hanji gives birth to three kittens in a besieged headquarters. It traces Armin’s transformation from measured strategist to sleep-starved chronicler on the edge of collapse, and the explosive return of Levi and Hanji, two veterans presumed long dead who have spent five years in secluded peace as “the unaware” in a forest cabin. Horror, guilt, and fragile loyalty collide as a new plague corrodes bodies and trust alike.

Across four long chapters, The Rumbling That Never Ended explores how a group of war-broken cats confront a second cataclysm they do not understand, and how, in the middle of infection and hatred, three tiny lives named June, Mira, and Udo force everyone to decide what kind of future they are still willing to fight for.

Chapter One: The First Recorded Infection

The story opens in the Alliance headquarters on a scarred Paradis, now a tense warren of cats who fought on the “wrong” side of history in the eyes of their own people. Armin, a tall golden tabby with ocean-blue eyes, shares command with Jean, holding together a faction that opposed the Rumbling but did nothing to stop it and now bears the weight of that failure. Their enemies are not just the Jaegerists who run the island, but also the citizens who hate both factions for the massacre beyond the seas.

Reiner, a large blond tabby soldier, returns from a solitary visit to the beach. He waded alone into waters warmed by a ruined climate and the melted glaciers that freed a timeworn microorganism. It slid into his body through the smallest break in his skin and settled there, quiet at first. In the first days, he feels only a vague sickness, a fading appetite, irritability he cannot name. Stage one of the infection passes almost unnoticed: Reiner looks thinner, more ragged, but the Alliance is used to exhaustion and trauma. Armin, always observant, begins to make notes in a battered journal all the same, unsettled by something in Reiner’s eyes.

Tension among the Alliance already runs high. Armin and Jean are juggling rumors of Eren sightings, crackdowns from Jaegerist patrols, and citizens who spit slurs at them in the streets. Mikasa, Annie, Connie, Falco, Gabi, Pieck, Magath, and Yelena form a frayed circle of uneasy comrades, veterans of a war that ended the world but not their nightmares. Everyone believes Levi and Hanji, the last veterans from before Wall Maria fell, died just before the Rumbling, their absence a silent wound in the group’s history. Only Pieck and Magath know that in truth the two slipped away into the forest, swearing them to secrecy.

As Reiner descends into stage two, his body begins to betray him. He becomes dangerously thin, his fur clumps with neglect, his tail droops, and there is a distant glaze in his eyes. He drifts through headquarters with restless steps, snapping without warning. Irritability curdles into volatility, and the Alliance’s strained peace starts to crack. An argument with Annie explodes one day when she confronts him about his behavior. He lunges, claws flashing, his movements jerky and wrong. Annie escapes with her hide intact but emerges shaking, rattled less by the attack than by the way Reiner’s gaze did not seem to recognize her.

Armin’s journal becomes the spine of the chapter. He starts cataloging what he calls “the stages” of Reiner’s condition: time since exposure, behavioral shifts, physical decay. He writes late into the night while the headquarters sleeps, his neat script breaking into cramped lines as he tries to impose order on something unnamed and terrifying. A horror scholar in everything but name, he is calm at first, convinced that careful observation will keep disaster at bay. Yet between the lines, fear grows. He has led others through Titans and genocide, but this is different. This is intimate, invisible, not born from one enemy they can see but from the very world they ruined.

By the end of Chapter One, Reiner’s condition marks him as the first recorded infected cat, and Armin’s journal has become both lifeline and curse. The Alliance suspects he is sick, possibly contagious, yet no one understands what has truly begun. The Rumbling ended the world, but the world is not quite finished with them.

Chapter Two: Quarantine, Escape, and the Cabin in the Woods

Chapter Two plunges fully into infection horror as Reiner crosses into stage three. Now there is no awareness in his clouded blue eyes. His irises go milky and blind, yet his hearing sharpens to an unnerving, predatory intensity. His gait slows in the corridors, but when sound touches his ears he can still sprint with terrifying bursts of speed, ears permanently pricked, claws permanently unsheathed.

Connie, Jean, and Falco are sent to check on Reiner after he barricades himself in his room for a full day. Connie, light grey with open, trusting eyes, calls to his old friend as they push inside. The response is instant and feral. The infected Reiner hurls himself at Connie, guided by sound rather than sight, raking claws down Connie’s shoulder and flank. Flesh tears, blood spills, and the room erupts into panic as Falco and Jean drag Connie away. Reiner crashes past them and flees the headquarters in a staggering run, vanishing into the forest.

Armin’s calm shatters. He orders Connie quarantined, insisting on strict isolation while grief rages around them. The Alliance has lost comrades to war, to rumbling, to betrayal, but never to something like this. Now a friend lies bleeding under watch, his wounds pulsing with the unknown. Connie soon begins to show the early signs of stage one infection: nausea, weight loss, irritability that does not feel like his own.

The headquarters becomes a haunted place. A patrol locates Reiner in a nearby forest as he slips into stage four. He is a walking corpse of a cat, making quiet, involuntary noises whenever sound brushes his ears. Fresh blood mats his fur, but they find no dead bodies nearby. For now, at least, Reiner seems to have attacked no one else. The patrol also spots a cabin in the woods but, spooked by Reiner and under strict orders to return quickly, they herd the infected warrior back to headquarters without investigating. The cabin becomes a whispered detail in Armin’s report, a note in the margin of his growing terror.

Back within the walls, Reiner is locked away in a deeper quarantine as he slides toward stage five. At night, the entire headquarters hears him. His hoarse bellows and skull rattle against the stone, a constant reminder that something inside their own ranks has crossed a line from comrade to monstrosity. No one sleeps well. Cats jerk awake with claws unsheathed, ears ringing with Reiner’s unending cries. Armin chronicles every symptom and timeline in his journal, but the act that once comforted him now feels like complicity. He is recording his friend’s disintegration in clinical detail, and each entry leaves his paws trembling.

The political landscape frays along with Armin’s composure. Jean argues that they should seek help from the Jaegerists or at least inform them about the infection, but Armin fears what Zeke would do with such knowledge. Citizens already hate the Alliance. If the infection leaks into the wider population, they will blame Armin’s faction, not the warming seas. He is trapped: tell the truth and risk being crushed, or keep the secret and gamble with everyone’s lives.

Driven by his need for answers and a nagging curiosity about the untouched cabin the patrol ignored, Armin sets out with Jean to investigate it personally. He needs somewhere the infection might have spread, some potential second site, but he also senses something else lurking in that omission. The forest outside headquarters carries Reiner’s scent and the heavy silence of a land that survived the Rumbling only to nurse new nightmares.

Inside the cabin he and Jean discover two ghosts who never died.

Levi, a compact black tabby scarred and partly blind, stands ready to defend the doorway. Beside him, Hanji, a tall russet tabby with an eyepatch dangling unused and a swollen belly that gives away her pregnancy, peeks from behind his shoulder, ashamed and tense. They have lived apart from the ruined world for five years, part of the tiny category Armin’s notes call “the unaware”. They know nothing of Jaegerist rule, nothing of the citizens’ hatred, nothing of the infection beyond the recent attack in the woods, when a wild eyed cat tried to tear into Hanji and Levi fought him off without taking a scratch.

The reunion is not warm. Armin’s grief at their absence, his years of assuming them dead, and his guilt for surviving all fuse into rage at their self chosen exile. He accuses them of abandoning their posts, their students, their home. Levi stays bristling-silent. Hanji flinches but does not argue, looking at Armin with one seeing eye that carries its own ledger of wounds. It is only when Jean steps in, and when Armin’s anger gutters under the undeniable relief of seeing them alive, that the mood softens. Armin suddenly realizes these two have been living in a fragile peace that he is about to shatter with infection and politics.

The chapter ends with Levi and Hanji agreeing to leave their cabin and return to headquarters, their old eyepatch and war posture reclaimed. The cabin, once a sanctuary, is declared unsafe. Whatever attacked Reiner is already there, somewhere in the trees and rivers. The Alliance’s last veterans are coming home, and with them the past they represent. Armin walks back between them, journal held tight, knowing that he has pulled them into a story that might devour them all.

Chapter Three: The Return of Legends and the Weight of Abandonment

Chapter Three pivots from pure infection horror to social fracture and personal confrontation, though the sickness never leaves the background. Headquarters reels when Levi and Hanji walk through the door. For the older Alliance cats who once followed them, it is like seeing ghosts raised out of battlefields they never buried. For the newer soldiers who grew up on tales of their exploits and on Floch’s story that Zeke killed them, it feels like betrayal made flesh.

Armin, who once saw Levi and Hanji as parental figures in the chaos before the Rumbling, now leads a faction that has defined itself without them. He splits his narrative attention between his own struggle to reconcile love and resentment, and the charged way others see these returning figures. Hanji resumes wearing the eyepatch she had set aside in the quiet of the cabin, only removing it in private when alone with Levi. Levi never leaves her side, his protectiveness sharpened by her visible pregnancy.

Outside their old circle, the welcome is much colder. Younger Alliance soldiers, who never fought under Hanji’s command and only know Levi as legend, resent the veterans for disappearing while everyone else faced the Rumbling’s aftermath and the citizens’ hatred. They mutter that Levi and Hanji chose a life of comfort while others bled. Older comrades like Mikasa, Annie, and the Marleyan contingent feel a quieter hurt, but relief outweighs anger. They know what these two survivors carried even before the Rumbling.

The infection continues its merciless timeline. Reiner is in full stage five, a hive minded, skeletal creature confined as tightly as the Alliance can manage without killing him outright. Connie, now in stage two, grows gaunt and unpredictable, swinging from lucidity to snarling confusion. His tail drags, his fur mats, he forgets conversations moments after they happen. These two infected bodies become the center of Hanji and Armin’s desperate research. It is not Titan science, but Hanji’s old obsession with the unknown resurfaces, this time chained to the urgent need to save friends rather than dissect enemies.

Hanji largely refuses to engage with the whispers and open scorn around her. She has more pressing problems than defending her own choices. There is the infection devouring Reiner and Connie, the need to map its stages and possible vectors alongside Armin, and the undeniable weight of her pregnant body. She puts her mind to work cataloging data with Armin: time between stages, behavioral clues, possible explanations for why Reiner’s environment at the sea might have carried a primordial organism. When Armin pores over old notes that mention Ymir’s ancient microorganism, the text quietly acknowledges that these concepts might draw on external mythos and must be attributed in any published analysis.

Armin himself is unraveling. He started out trying to be calm and analytical, but Reiner’s escape and Connie’s infection carved deep into his composure. Sleep slips away. He journals every significant event with a compulsive thoroughness that no longer feels like control but like helpless documentation. He blames himself for not seeing the infection earlier, for not locking Reiner away sooner, for bringing Levi and Hanji back into the line of fire. When nameless younger soldiers question whether Levi and Hanji deserve the protection they receive, Armin clashes with them, teeth bared, old loyalties clashing with new doubts.

The social powder keg finally detonates when a younger Alliance soldier snarls an insult about Hanji’s pregnancy, mocking the idea of bringing kittens into this ruined world and accusing Hanji of hiding behind her swollen belly while others suffer. Years of bottled anger erupt in Levi. Once he fought Titans and men with precise efficiency, now he throws himself into a brutal physical fight with the insolent cat. Despite five years of peace, his movements are not rusty at all. Claws and teeth flash. by the time Armin forces his way between them, the younger soldier lies bloodied and shaking, terror in his eyes as he finally understands that the stories about Levi were not embellished.

This incident rips open every fracture line in the Alliance. Some argue that Levi has proven he is still the commander they once needed. Others say he is a relic whose brutality has no place in this fragile post genocide world. Armin stands in the middle, reeling from his own instinctive urge to defend Levi and Hanji, then doubting himself for that same loyalty. Once his moral compass always pointed toward them. Now, as leader, he must weigh them against everyone else. He reprimands Levi for the ferocity of the attack but also refuses to let anyone threaten Hanji or the kittens she carries.

Chapter Three closes with Hanji and Armin making crucial breakthroughs in understanding the infection’s progression and limited containment tactics. There is still no cure, but they begin to see patterns that could allow them to slow spread or identify early signs among citizens. Headquarters becomes a kind of last safe place, fortified both against Jaegerist scrutiny and against the infected beings inside. Socially, however, nothing is safe. Distrust of Levi and Hanji lingers, wary respect battling resentment. Armin’s journal gains a second purpose: it is not just a record of the infection anymore, but of how leadership fractures under fear.

Chapter Four: Three Kits in a Dying World

The final chapter stretches from late pregnancy to birth and its aftermath, balancing continuing horror with the fragile, almost stubborn emergence of hope. The infection has not vanished. Reiner remains in final stage confinement, more symbol than soldier now, a walking reminder of what the microorganism can do. Connie’s condition worsens, his body hardly more than bones under skin, yet he occasionally has startling flashes of himself that break everyone’s hearts. Armin and Hanji’s work yields partial successes: better quarantine protocols, faster recognition of early symptoms, a few interventions that appear to delay full mental collapse in newly exposed subjects. But there is no cure, no way to undo Reiner’s fate or fully save Connie.

Outside the headquarters, the island remains hostile. Citizens continue to despise both Jaegerists and Alliance for the genocide wrought by the Rumbling. Jaegerist patrols watch the Alliance with suspicion, and rumors about a new “plague” begin to circulate in back alleys and taverns, though no one yet understands its origin. Eren remains a ghost story haunting the borders of the island, occasionally sighted then gone, allegiance unknown.

Within this pressure cooker, Hanji’s pregnancy advances toward the three month mark of feline gestation. Her body is heavier, her movements slower, and the eyepatch is firmly back in place. She and Levi sleep in headquarters now, their old cabin abandoned as a potential contamination site. Levi’s protectiveness, already intense, borders on obsessive. He rarely leaves her side, stalking the corridors like a small, dark guardian with half a ruined paw and a gaze that dares anyone to speak against her. To some he is a menace, to others a necessary shield against a world that has decided their lives are expendable.

Armin’s narrative focus shifts to observe how this impending birth reframes the infection crisis. For some Alliance members, the idea of kittens in such a world feels obscene. For others, it represents the first genuine future they have been able to imagine since the walls fell. Armin himself teeters between these poles. He helps Hanji with her research, pores over his notes, and in rare moments of quiet, catches himself imagining what kind of world June, Mira, and Udo might inherit. He clashes again and again with nameless detractors who want Levi and Hanji gone, yet eventually recomposes himself and defends them, publicly reaffirming their right to this fragile family and wishing their kittens well.

As labor nears, the headquarters sits on a knife’s edge. Infection responses are better rehearsed but no less terrifying. Patrols move like clockwork. Every cough gets a second look. Armin and Hanji continue to refine their joint record of the microorganism’s behavior, always aware they are working with a force that predates and outlasts all their wars. They resolve that whatever happens, their notes will not be lost. If the Alliance falls, someone, someday, must know what transpired here.

Hanji’s labor begins amid the ongoing tension, not with fanfare but with the quiet, insistent waves of pain that pull her inward. The entire headquarters seems to hold its breath. Levi hovers so close that others must physically herd him out at key moments. Old comrades gather nearby, a loose ring of cats whose shared history is written in scars. Younger soldiers pace, some anxious, some scornful, all unable to ignore the gravity of this moment.

The birth is fraught and visceral. Hanji’s body, already battered by years of war and science, now strains to bring three new lives into a world that has given her little reason to trust it. The infection, the Rumbling, the hatred of citizens, even the ghost of Eren all hang over the scene like storm clouds. Yet against that backdrop, three kittens arrive one by one: June, Mira, and finally Udo, named after a Marleyan friend Gabi and Falco lost long ago when he died far from Paradis, before most of them ever met him. When they see how much the little kit resembles him, they weep.

In the days that follow, Headquarters rearranges itself around these three tiny bodies. The story allows short glimpses of each: June’s first wobbly steps, Mira’s tendency to burrow into Hanji’s fur, Udo’s sleepy resemblance to the dead friend whose name he carries. Not enough time passes to fully develop their personalities, but their presence forces every adult cat to confront what they believe about the future. Some begin to soften, grudgingly helping to watch over the kits. Others remain distant, unable to forgive Levi and Hanji or to imagine that anything good can grow out of genocide and plague.

Armin, ever the chronicler, adds a new kind of entry to his journal. Alongside charts of infection stages and sketches of Reiner’s decaying posture, he now writes observations of June’s first blink, Mira’s first startled reaction to Reiner’s distant cries, Udo’s steady breathing against Levi’s chest. The juxtaposition is brutal and deliberate. On one page, death and decay. On the next, clumsy life.

By the end of the book, the infection crisis is not solved. The microorganism still exists in the seas and soil. The Alliance maintains a tenuous control over its spread, armed with partial understanding and fragile containment tactics rather than any true cure. Relations with the Jaegerists and the citizens remain fraught. Distrust of Levi and Hanji has dulled but not vanished. Armin’s leadership is more weathered, more conflicted, but also more honest about his limits.

The final scenes do not offer easy catharsis. Instead, they linger on small, stubborn acts of care: Levi watching over Hanji and the kits during a rare quiet night, Hanji and Armin bent over their notes while June, Mira, and Udo sleep nearby, Connie’s gaunt form seen from a distance as he rests in his quarantine space, half remembered jokes on his tongue. Somewhere outside, Reiner’s stage five body shifts in its pen, still tethered by bonds of former friendship as much as by chains.

The Rumbling That Never Ended closes on a bittersweet image of the three kittens curled together, their tiny bodies breathing in unison while, outside their room, a headquarters of broken survivors continues the grim work of understanding the infection and surviving their own history. The world remains dark, the horror unresolved, but the existence of June, Mira, and Udo proves that even in a landscape shaped by genocide and plague, some cats still choose to create and protect fragile new life. In Armin’s chronicle, that choice matters as much as any battle ever did.