The first thing you notice is the bite. It stings, throbs, bleeds. It's not a clean wound, not like a minor bite from a dog or cat. Not a few neat little punctures, or some gashes that would at least stitch up neatly. No. It's an ugly rip, the torn flesh from blunt teeth that are not and never were designed for biting. It's still startling how the human's muscles are powerful enough to bite through skin like that anyway. Strong enough to rip out a chunk, if you got snagged in a soft, tender place.

The next thing you notice is the infection. If you're lucky, you can use some precious water to wash off the bite and some gauze to wrap it, but most people aren't so lucky. Most have to rely on strips of acceptably dirty, sweaty fabric from old clothes, if they can even spare that much. Most don't want to "waste" a resource as precious as clean, drinkable water. So infection sets in fast and hard. Within a few days, your wound is a stinking, oozing mess. It's painful. Painful to look at, painful to touch, painful to move. It's swollen as your body desperately tries to fight the concoction of bacteria introduced from being bitten by a decomposing mouth. Then it itches. It itches madly. It itches so much you won't be able to sleep. It itches so bad that if you stop focusing on it, you'll find a surge of new pain as you've absently scratched it and started to bleed again, so you have to keep thinking about how badly you should never scratch the itch. Maybe you'll have a raw spot, where you've been tricking your mind into relief by scratching just above the wound. You might even have dug new cuts into your flesh, more wounds to host infection, more places to sting with pain. 

The itching is the virus taking hold, but you don't know that.

All you know is that you have a swollen, itchy, stinking bite. 

Next comes from the infection. You'll start to get a fever. Your bite will swell more, and feel hot. But mostly, you get a fever. Nobody feels good then. You'll switch between being far too hot to freezing cold, you'll sweat in a tank top in the middle of the night or you'll shiver under as many layers as you could possibly procure. You'll get nauseous, so you won't want to eat or drink, leading to more nausea as you dehydrate. As it progresses, you'll feel weaker. It might be harder to breathe normally, you might even feel your heart racing as you sit still. Even just a ten minute walk will exhaust you, but your group has to keep moving. As it goes on, you'll find it harder to keep your grasp on reality. The pain, the nausea, the smell, the weakness, it all blends into one as the virus takes its hold in your mind.

Oh, yeah. It's now when the virus kicks into action, having made it to your brain. Maybe you were taking care of yourself, and the infection actually hadn't gotten that bad through sheer luck and winning the biological lottery. But now the virus has made it to its destination. The first thing it does is impair your immune system. After all, it can't have you fighting it off. It doesn't want you healthy. If you're healthy, things get complicated. That natural system has to go, so away it goes. If you were sick, you'll suddenly find yourself getting sicker.

Next, it overrides your appetite. Maybe you were just craving crackers and water, maybe you didn't want anything, maybe you ate through the nausea just fine. It changes that. Subtly, day by day, it makes you feel hungrier and hungrier. The kind of hunger that sits in your belly and gnaws at your bones from the inside. It's also an unnatural craving for meat. Fresh meat, red, straight from the bone. Still warm, still flowing with life. You'll be able to smell your friends now, or the recent tracks of others if you're alone. Of course, you've always been able to smell them, but it got filed away into your subconscious. But now you're aware of it, because that virus tells you it's important. And they will smell decadent. 

It's all the virus, scrambling your neurons to connect hunger and appetite to humans instead of a plate of cookies, cake, fruit, veggies and juicy steak, mashed potatoes and meaty stew, anything you used to enjoy. It will change how you taste. Sweets will stick to your throat, bitters are more bitter, and if you're lucky to have a nice plate of steak, that fresh-grilled meat will taste rotten. What you crave is no longer any real sustenance, your mind has been altered. Now, you won't see a warm hand to hold, because the sight of bare, moving skin activates your salivary glands. The urge to sink your teeth into the soft flesh on a wrist or neck will be overwhelming in the blur of sickness from the infection. And if you do actually bite, especially if you taste blood, the virus will reward you. It'll flood your system with dopamine, and afterwards, for just a few moments, the edge of that hunger will release. It hopes you'll get addicted. It wants you to crave more biting, more flesh, because it feels right, because maybe, just maybe, if you eat enough the hunger will finally go away. 

Finally, it'll change your sense of fear as well. Dangerous situations that instinctively make humans nervous won't affect you. If anything, you'll crave the rush that deadly moments give you, the rush of feeling real and grounded in the midst of the foggy world from the mess in your system. Just fourteen days, and the virus is fully mature and ready to spread. Now, it needs you to die. So it makes you reckless. It does its best to turn a regular, self-preserving person into an actual train wreck. It will actually give you dopamine and serotonin when you get an injury, in a ratio equal to the wound. So, you'll die the happiest you could possibly be from something like a knife through the heart, or a shot through the gut. Some people are driven to jump from heights and impale themselves on something below, or even just hit the pavement and let themselves die wrapped in the gentle hands of joy. Some will just injure themselves, without the help of gravity. Some will aggressively antagonize other humans, hoping they'll eg them into a violent, deadly fight. But generally those people were already jerks in the first place.

Once you've died, however you died, the virus can take over. Because, this whole time, it wasn't really a virus. It was a worm, which starts so tiny you would never stand a chance of noticing it. Tinier even than those little red bugs you might see crawling over paper when you're out in the woods, so small that if you brush your hand over them they become nothing more than a smear of coppery brown. So small and fragile, they couldn't possibly survive outside of a host. But inside a host, they grow. They grow and grow, so thoroughly burying themselves in your brain they may as well have always been in it. When you die, they can finally take control of your muscles, no longer held back by the complexities of the human mind. This is why zombies shuffle and jerk around so awkwardly. They're merely puppets, meaty sacks of flesh controlled from inside by a worm that's found the strings. It knows just which ones to pull which way to make motion happen. It doesn't breathe, not really, all it might use is that sense of smell it learned while you were alive. It will use hearing, because those little organs in your ear won't stop feeling sound just because your body is dead. All those other systems aren't essential for a worm that's single purpose in life is now to find hosts for its own horrible offspring. Because that worm isn't alone. 

It's not one worm. It's dozens of them, all now breeding and gathering their safely hatched larvae on the cold teeth and tongue of the corpse within which they reside. And yes, they might have been able to spread before now, if your environment was just right to keep your mouth the right temperature for this breeding. Yes, you might have infected others while you still lived and breathed in your own skin.

You see, those adults can't reproduce at the natural body temperature of a human, let alone the temperatures they can reach during the height of a fever. So they need that host to die and cool off. It just takes a day. Just one day for enough eggs, enough larvae to let that monstrous parasite begin searching for a new host. Those larvae can't grow in the cold, decomposing bodies of the dead. Although, the adults are surprisingly resilient, uncharacteristically long-lived, for a parasite. And so, the zombie rises, shuffling after any hint of breathing humans to continue their cycle of life and death.

If you crack open a zombie's skull without blasting the contents within into oblivion, you might be able to find dozens of these foot-long worms wiggling in distaste at their unexpected situation.

Of course, all of this depends on the physical and mental toll that getting a severe infection does. Ideally, the parasite doesn't even get to the stage where it has to drive you to seek death, because septic shock has already come and destroyed you from the inside out. So, in theory, it is survivable. If you aren't wracked with sickness, if you have a strong will, you might be able to fight the parasites long enough for them to die. You might just be able to recover.

But that's never happened. Besides, would you even want to survive? How permanent, how treatable are the alterations these parasitic worms cause? No one knows.

Here it is, the zombie "virus" and how it works written in a weirdly disassociated perspective, specifically for the few bitten!hermit headcanons. Feel free to ask questions and write stories! Please tag me in them @basaltdragon, I wanna hear it all •v•

I'm sorry if this triggers anybody (including mod) in any way, it is... a Lot.