Deep within the favelas of Rio de Janeiro, Brazil, heat and clamor were the eternal backdrop.
Bruce Banner huddled in his cramped shack, his faded undershirt soaked with sweat.
The open physics journals and scattered radio parts on his table were his fragile fortress against the Beast within, a way to maintain his 'humanity'.
However, this fortress was now under an invisible assault from afar.
... "Repeat, urgent news! An extraordinary large-scale energy burst has occurred in the Pacific Ocean, and a United Nations subsidiary has confirmed its threat level as 'Dragon-Class', with the target suspected to be the Tokyo area of Japan! Nations are activating emergency response mechanisms..."
The old radio, which he had repaired to listen to outside news, was intermittently broadcasting this World-shattering news.
The announcer's voice had lost its usual composure, tinged with unconcealed panic.
Dr. Banner's fingers, holding a precision screwdriver, suddenly tightened, his knuckles turning white.
Dragon-Class.
The word was like a cold needle, piercing his taut nerves.
Although he was far from the eye of the storm, he was not entirely ignorant of the outside World.
Through scattered newspapers and cautious internet browsing, he broadly understood the threat level classification system introduced by the Hero Association—Dragon-Class meant a city-destroying catastrophe.
And it was Tokyo.
That vibrant and orderly super-metropolis he had visited many times for academic conferences.
A familiar, terrifying heat surged uncontrollably deep within his veins.
It was him—Hulk.
He seemed to sense the immense malice and destructive aura from afar, becoming restless, letting out a deep, violent roar within his mental cage.
"No... quiet... not now..." Dr. Banner closed his eyes, his forehead pressed against the cold, damp wall, fully employing his well-honed breathing control techniques, trying to suppress the monster about to break free.
Every global crisis of this magnitude was an extreme test of his willpower.
He was not afraid of participating in the fight, but of losing control, of the incalculable collateral damage Hulk might cause in that chaos.
The news on the radio continued, mentioning that the Hero Association had already responded and that panic was spreading globally.
In Dr. Banner's mind, information about that organization uncontrollably resurfaced—efficient, systematic, possessing unknown technology, and... Kingpin, the leader who dared to confront multiple forces simultaneously.
"Can they... stop it?" A small thought sprouted in his heart.
If even that seemingly omnipotent Association needed to go all out, and might still fail to stop it...
Just then, an extremely faint vibration, definitely not from any known sound source in the favela, was keenly detected by him.
It wasn't the roar of cars, nor the beat of samba drums, but a... deep, specific frequency of engine roar, as if from above the clouds.
He suddenly looked up, and despite the thick walls and intricate shanties, his gaze seemed to penetrate everything, looking towards the northern sky.
"Quinjet..."
He recognized that sound.
It was S.H.I.E.L.D.'s iconic vehicle.
They had come.
Not for him (at least not this time), but towards the Pacific, towards Tokyo.
The Avengers were deploying.
Almost at the same moment Dr. Banner detected that faint engine sound, at S.H.I.E.L.D.'s Trident Headquarters.
Nick Fury's single eye scanned the suffocating data of Sea King and the unfolding chaos along Tokyo Bay on the main screen, then issued a concise and cold command into his communicator:
"Initiate 'Avengers Protocol'."
The command was like a stone dropped into a still lake, creating ripples in several specific corners of the World.
In a humble apartment in Brooklyn, New York, Steve Rogers, who had just finished his morning run and was about to enjoy a simple breakfast, heard his retro-style communicator on the table buzz urgently.
The screen lit up, displaying the S.H.I.E.L.D. eagle emblem and the words "Maximum Alert."
He picked up the communicator, saw the "Dragon-Class Threat" and the location of Tokyo, and a flicker of solemnity crossed his clear blue eyes, but without the slightest hesitation.
He put down the bitten toast, picked up his star-spangled shield leaning against the wall, and walked resolutely towards the door.
On the top platform of Stark Tower, the red and gold Iron Man armor was already in position, its thrusters spewing an ethereal blue exhaust.
Tony Stark's faceplate closed, sealing him off from the outside World, and from any emotions he might reveal.
Jarvis's voice sounded on the internal channel: "Sir, all systems online.
Remote deployment channel calibrated, target point: outer Tokyo Bay."
"Keep the channel clean, Jarvis.
Let's go give that big fish a 'physical exam'."
Tony's voice, through the faceplate, carried a deliberately casual tone, but the clenched fists of the armor betrayed his true readiness.
Meanwhile, thousands of miles away, above a mysterious sea area in Northern Europe, a stealth Quinjet tore through the clouds, speeding eastward at maximum velocity.
Inside the cabin, Natasha Romanoff (Black Widow) expertly checked her gear, while Clint Barton (Hawkeye) rested with his eyes closed, his fingers unconsciously caressing the specialized arrows in his quiver, as if listening to the whispers of the wind.
"Fury went all out," Natasha broke the silence in the cabin, her voice as calm as ever, "Dragon-Class... the first truly full-team operation."
Hawkeye opened his eyes, his gaze sharp: "Good.
Let's see if our 'alliance' can really handle this kind of big show."
Their objective was not to go directly to Tokyo Bay, but to meet Stark and Captain Rogers in a designated sea area to form the complete initial Avengers team, and then proceed together to the battlefield.
And in the favela of Rio, Dr. Banner still maintained his posture, leaning against the wall, his undershirt soaked with sweat.
The agitation within him slightly intensified due to the passing Quinjet in the distance, and Hulk's roar echoed in his mind.
He heard the radio reports of public panic, and saw the imagined scenes of a potential inferno in Tokyo Bay.
He also recalled the Hero Association's introduction to the "Mind and Body Health Center," and Kingpin's theories on "order" and "systematization."
An unprecedented impulse, mixed with deep fear and a faint glimmer of hope almost drowned by despair, grew wildly in his heart.
Perhaps... perhaps this time would be different?
Perhaps on that chaotic battlefield, when everyone was giving their all against a common threat... perhaps... Hulk's strength could be guided, could be... needed?
The thought sent shivers down his spine, yet it held a fatal allure.
He slowly straightened up and walked to the small window that overlooked the cluttered alleyway and a sliver of sky.
In the distance, the faint contrail left by the Quinjet had long since dissipated into the clouds.
He looked down at his hands, seemingly ordinary, yet containing destructive power.
On the radio, the latest news about Sea King approaching Tokyo, about the Hero Association's front lines being strained, and about the World holding its breath, continued to pour in.
The storm had made landfall, and the Guardians of the World were converging from all directions, rushing to that battlefield destined to become scorched earth.
He, Bruce Banner, or rather, the him within him, where should he go?
Silence spread through the stuffy shack, with only the radio's voice and the increasingly clear roar of the monster within him counting down.