Karl's watched the events unfold before his eyes...
In a dying world, Peter Parker was in a struggle he could not win. Two months into the apocalypse, society was deep in dissolution. What was once lively New York now stood but a shadow of its old self, trudging around with walking dead roaming the streets, flames eating into the sky.
Across the city, Peter had swung to his might to save every single life possible. His once strong, so confident demeanor was now haunted by a sense of hopelessness. Around every alley, he turned into and every building he went into were the groans of those who were dead and the screams of those few survivors who were still hanging for life.
As much as Peter landed on a rooftop, his mind flashed back to that fateful day. It began with reports of a flu-like virus but only weeks later, the city was overwhelmed with the infected. The Avengers, the Fantastic Four—those heroes he really looked up to—had fallen or vanished. He stood alone, obligated to protect his loved ones.
A pang of sorrow struck Peter as he suddenly remembered Aunt May. One day, Peter came home to find her lifeless body lying on the kitchen floor—what was left of it. Some housebreaking zombies had eaten her up. He knelt beside her, tears running down his face as he felt his heart shred a little more with every passing second.
The memory shifted, and Peter found himself in his apartment with Mary Jane. They had been holding onto each other, trying to find solace amidst the chaos. But fate was cruel. A seemingly harmless, stray cat found its way into their home. They didn't notice its erratic behavior until it was too late. The cat, infected with the virus, bit Mary Jane.
Peter's hands shook with her in his arms as he watched in horror as the infection spread. Her eyes turned glassy, and she began to convulse. He wanted to save her, but it was beyond his control. She turned her eyes toward him, full of fear but burning love. "Peter, don't let me become one of them," she whispered. But he didn't have the heart to kill her.
Instead, he did what he could think of. He locked her in his basement, with the hope of somehow, someway, finding a cure. Every day he went down to the basement, bringing her food, talking to her, trying to keep her memories alive. But she was not the same Mary Jane he remembers. Her fiery locks had lost their color, becoming matted and grimy. Her eyes were a blank and lifeless expression. All she wanted to feed on was human flesh and blood.
Deep inside, Peter knew she was gone, yet he would not surrender hope. Even after the city fell and losing contact with his few remaining friends, he still held on to that thin fraying thread of hope. Now, he buried himself with research in the hope of a cure for the virus. He had rummaged through all the labs, libraries, and even old superhero bases for anything that would help him. By then, he was desperate. Every failed attempt, every dead end weighed heavily upon him. The world was on the brink of doom, and all hope seemed lost.
Karl watched how memories of Peter were thrashed, feeling every ounce of the pain and sorrow. The world lost a hero, not in a blaze of glory but in a quiet, tormenting agony of loss. Peter Parker, the Amazing Spiderman, is reduced to a mere shell of what he used to be, consumed by despair and desperation.
Peter worked on a serum. He captured zombies from the streets and injected them with the cure, hoping and praying that it worked. But every single time, the test subject died. Then he thought of capturing humans, infecting them with the zombie virus, and then injecting the cure. If it doesn't cure zombies, maybe those newly infected humans might get cured.
But even in that most desperate of situations, he couldn't bear to hurt another living soul. He tried infecting the rats and mice from the lab but the cure would eventually kill them. For Karl, it was Peter's misery in understanding that he was unable to find a way to save Mary Jane. He sat on the cold, hard ground, tears streaming down his face, sobbing uncontrollably.
It was just another night in the apocalypse wasteland. Peter was working in his little lab, poring over notes and samples. His eyes had turned red from lack of sleep; his hands shook due to fatigue. All of a sudden, he felt a sharp stabbing pain in his chest. He clutched at his heart, thinking it was stress or just plain fatigue, but the pain only grew worse, spreading through him like fire.
He staggered into the bathroom and then to the mirror. His skin was white, his veins dark and defined. This reflection rippled, further distorting. He felt desperation and fear shooting through him. The thing he'd been trying to cure—the virus—had infected him somehow.
Karl gasped when he realized Peter was enduring his last minutes of conscious time. He imagined each little bit of Peter's fear and panic as the virus raged in his system. He was turning into one of those very monsters against which he had sworn to fight until the end.
In desperation, he injected himself with a serum that he had been working on. It was untested, a last-ditch effort at saving himself. His body convulsed under an increased wave of pain as the serum inflamed him like liquid fire in his veins. He collapsed hard to the floor, his vision blurring. The last thing he saw before darkness took him was Mary Jane's lifeless eyes staring at him from the cage.
When Peter woke up, he was no longer human. His body had mutated and twisted itself into an unsightly form. He was stronger, faster, his mind slipping away as the virus consumed what remained of him—changing him into one of these monsters he had been fighting against. Yet, for some reason, he retained his sanity. It might be the serum's effect or his DNA. So instead of wasting time, he picked up work on the cure once more.
He threw away his moral code and rounded up humans from the settlements nearby. He injected them with the zombie virus and then injected them with the serum he had been working on. If they survive, he would again inject them with the virus and then the cure. This had happened countless times but to no avail. The humans die upon injection of the serum.
Peter's desperation grew as he saw the failures of dead humans. He felt the virus taking hold of his mind, slowly eroding his humanity. He developed urges to eat raw flesh and blood. Being unable to hold it anymore, he went to blood bank facilities to quench his thirsting body. He wanted to stop but couldn't do so. At night, he hunted for animals due to his urge to eat raw meat.
As the virus reached its full potential, Karl felt what Peter felt. He was slowly ceasing to be human and becoming a monster, day by day.
He struggled to hang on to his humanity just a little while longer, to remind himself of the man he was, but the memories were slipping further and further away from him, replaced with a continuous hunger and rage. He prowled through the city, attacking anything in motion, for his once heroic instincts had been replaced by the most base instincts ever.
Before Peter lost control, he had managed to come up with a cure that stopped the progress of the virus temporarily. Any infected person who, upon being given the cure within ten minutes, shall be saved; however, they must take the serum every 48 hours without fail to prevent the virus from flaring up again.
Karl could only stand by and watch as the final moments of Peter Parker passed away. He felt his anguish, his sorrow, knowing that he could never save himself but others he could. With the last of his strength, he crawled to one wall of his lab and scrawled in red:
"If you're reading this, I'm probably dead. But there's still hope. I have exhausted my last resources in finding the cure. But with my formula, you should be able to synthesize more. Shield should have a facility to synthesize enough for everyone. I don't know if their facilities are still functional or not. But please, if you care about humanity, use it to save as many people as you can. Maybe you should be able to develop a permanent cure. Succeed where I failed."
The message written, Peter slumped to the ground as his body finally gave in to the virus.
The city lay in ruins—lots of zombies and mutated animals everywhere. Peter, now fully spawned into the big monstrous version of himself, was unstoppable. He tore through the undead with unmatched ferocity, though he was no longer a hero—it only made him a monster driven by a need to destroy.