The computer beeps dispassionately, displaying the results of your most recent failure. "Damn it!" you shout, pounding your fist on the table in anger. Your assistant looks up in alarm.

"What's wrong, doctor?" she asks. You rest your head in your hand and sigh heavily.

"That's the twelfth sequence in a row that hasn't worked! I just don't know what I'm doing wrong." You shake your head despondently. "The gas for the generator won't last forever. We can only continue our research as long as we can keep these computers running."

"Don't worry," she says, trying to reassure you. "You're a brilliant geneticist. You'll figure it out."

"Oh, really?" you snap sarcastically. "Well, thank you so much for your misplaced confidence, Neesha!" Your anger at your own failures, always waiting there just beneath the surface, explodes out of you. "If I was really brilliant, maybe I wouldn't have allowed the whole fucking world to be overrun by goddamn zombies, now would I?!"

Neesha is momentarily shocked at your outburst, then she looks as if she is about to cry. Instead, she abruptly stands up and storms out of the room. "Shit," you say under your breath. You briefly consider just letting her leave and continuing with your work, but you are already feeling guilty about losing your temper.

You start the next sequence analyzing on the computer, and then follow her into the next room, where you find her staring out the window. In the distance, a few zombies can be seen outside the security fence, but you're not worried. Any dangerously large gathering and you would get an immediate alert.

"Look," you say, suddenly at a loss for words. "I... I'm sorry." She sniffs but says nothing. "I know you were just trying to make me feel better." You wait, but she remains silent. "The truth is, I'm not mad at you. I've been fighting this outbreak for years, and sometimes it feels like I haven't made any progress. You're a great assistant, but we've only been working together for two weeks. You don't understand the things I've gone through, how worn down I've become."

She finally turns and looks at you. There are many emotions in her eyes, but the biggest seems to be pity. She sighs. "You can't be so hard on yourself," she says with a small smile. "I had given up hope for years, but the work we've done in just the past two weeks..." She trails off. "It's been truly remarkable. We've made great progress."

"Do you really think so?" you ask, surprised.

She nods. "When you rescued me out there, I was just so relieved at first. I hadn't had a single person I could count on for so long. I wanted so much to find a way to thank you, but I didn't know how." She looks away. "You barely paid any attention to me, and I was so disappointed."

"I'm sorry..." you start to say again, but she holds up a hand to cut you off.

"I understand now how important your work is. And once I started to understand what you were doing, once you let me start to help you, I got so excited! There's still so much I don't understand, but it gave me something to care about again."

"I really should have let you help sooner," you say with sincere regret in your voice. "You're very smart, Neesha. You're honestly the best assistant I've ever had."

She perks up. "Really?"

"Really." You are both silent for a while, unsure of what else to say. "You know something, we've been working together for two weeks and I've never even asked you your last name."

Her eyes sparkle with amusement. "It's Pradesh," she says, holding out her hand. "Nice to finally meet you."

You grasp her hand, laughing. "Dr. Trent Carson," you say. "Likewise."

**********

You look back at the computer, which shows that it will be close to an hour before the next analysis is complete. "You want to take a break until the results are ready?" you ask.

"Yeah, I could use a break," Neesha replies. She gets a bottle of water for both of you and sits at the table. You sit down next to her. "So..." she starts tentatively. "You said you've been fighting this for years. Were you... part of the original CDC team?" You look away as painful memories come flooding back. Your parents, your girlfriend, your co-workers. "If you don't want to talk about it, that's ok!" she says hastily.

You briefly stay quiet, but the new connection you seem to have made with Neesha convinces you to open up. "No, it's ok," you say. "Yes, I was on the original team. Now... I'm the only one left." She reaches over and lays a hand on yours. You see the sorrow in her eyes. You have lost almost everything, but at least you weren't alone the whole time like her. You had cut yourself off from caring about any other survivors, you realize now, in order to keep yourself from getting hurt any more. But now you feel more sympathy for Neesha than you've felt for anyone in years.

"The original vaccine we were working on was supposed to prevent people from getting infected at all, but now that there are so few survivors left, I've decided to switch tactics. You see, most people don't know this, but the zombies are actually caused by two different viruses. The one we were trying to create a vaccine for is the main one, the one that actually causes the zombification. But it's a very extreme virus that causes fatal damage to the human body within hours. Without the second virus, nobody would have survived it."

"So, what's the second virus?" she asks, intensely curious.

"The second virus is much more subtle. It's like an immune system damper, keeping the body from fighting back against the zombie virus. But it also inhibits the zombie virus itself, keeping it from causing so much damage that you die. So you stay a zombie almost indefinitely, never healing and never dying. I like to call it the sleeper virus. It keeps their human side asleep, so they're completely controlled by the zombie side. But here's where there's a small hope that we can still save the world. The sleeper virus is physically very frail. And it's so good at inhibiting all kinds of biological processes that it destroys itself within a few weeks."

Neesha nods slowly, and you pause for a moment to let this sink in. She looks up at you, puzzled. "So why have the zombies survived for years then?" she asks.

You chuckle. "It's ironic, but it's because they live mostly in groups. It's like the opposite of herd immunity. When the sleeper virus dies in one zombie, it just gets immediately reinfected by another. As you can probably guess, zombies are highly efficient disease vectors."

Neesha's eyes light up. "So now you're trying to make a vaccine for the sleeper virus!" she exclaims.

"Exactly," you say, nodding. "Their bodies have existed with the zombie virus for years, growing accustomed to it. If they were suddenly immune to the sleeper virus, most of them would probably recover."

"That's amazing," Neesha mutters to herself, now deep in thought. You can see the wheels turning in her mind already. Her exceptional analytical skills were the reason you started working with her in the first place, and, since you're being so honest with yourself all of a sudden, why you're so attracted to her. Of course, her incredible body doesn't hurt either. You're sure she's caught you staring at her lovely tits several times, although she hasn't said anything about it. At least, you think to yourself, she doesn't seem to mind. In fact, now that you're thinking about it, she actually seems to enjoy the attention.

"Wait," she says, shaking you out of your increasingly lewd thoughts. "Zombies must get separated from their groups sometimes. If they recover at that point, why isn't the world full of recovered zombies?"

"Well, they can get rezombified or killed, like anyone else. Plus, the zombie virus attacks some higher brain functions more than others, especially memory. It's possible they don't remember being zombies." You sigh deeply. "You know, you're the first person I've explained all this to in years. It's kind of a load off my mind, like I don't have to carry the responsibility for the whole human race by myself anymore."

Neesha slips her hand into yours and squeezes it gently. "You don't have to carry the weight of the world by yourself. I'll help." She smiles at you, the first real smile you've seen from her today. It strikes you for the first time just how beautiful she is.

"Unfortunately, that doesn't make our job any easier. We already failed to make a vaccine for the zombie virus, and making one for the sleeper virus will be much harder. Immuno-compromising viruses are the hardest ones to make vaccines for, and this one is so elusive. Hell, we didn't even know about it until the global pandemic was well under way."

She looks glum for a moment, but then slaps her hand on the table. "Well, we'll just have to do it then!" she exclaims, with more than a little bit of bravado.

Her optimism lifts your heart, and you wonder again how you could have spent weeks not noticing what an amazing woman she is. You suddenly realize that she has noticed you staring at her. You blush and look away, embarrassed. Neesha places her hand on your arm and gives you a different kind of smile. "I know something we could do to relax a little," she says suggestively.

"Uhhhh..." you say, trying to form a coherent thought. Neesha giggles, delighted at your befuddlement. She leans forward and kisses you softly. After a few more moments of shock, your brain gets into gear, and you kiss her back, sliding the tip of your tongue into her mouth.

Your stomach does backflips at the feeling of her lips gently sucking on your tongue. She giggles again and whispers into your ear, "Let's go upstairs."

**********

Neesha leads you eagerly up the stairs and into the bedroom. She kisses you again, more passionately, then shoves you down on the bed and climbs on top of you. Your breathing quickens. "Neesha," you say, gulping as she kisses each of your fingers, "I'm sorry if I was a jerk these last few weeks..." She puts a finger to your lips to stop you.

"Shhhh. We were in danger, and then there was so much work to do. There wasn't time for being nice. But I have been wanting this since the day we met." She leans down and slowly traces her tongue along your jawline. Her mouth meets yours as she begins to unbutton your shirt.

Neesha runs her hands across your bare chest with a sigh. You reach for her shirt, but she stops you. "You just relax, doctor," she says with a grin that drips of promised pleasure. "Let me take care of everything."

"Please, call me Trent," you say with a wink. She giggles again, a joyful peal that sends your heart reeling.

"Very well," she replies. She slowly peels her shirt off over her head, letting her gorgeous breasts spring free. "Now touch me, Trent," she commands.

"Yes ma'am," you say, running your hands up her sides and across the soft skin of her tits. Neesha closes her eyes and sucks in a breath through her teeth with a hissing sound. Her nipples come to life, hard under your fingers. You gently squeeze her firm breasts, enjoying their weight in your hands.

"Oh yes, Trent, that feels so good," Neesha moans. She begins to wiggle her hips, grinding against you, rubbing her soft mound up and down on your hard cock. It feels amazing even through two layers of pants. Neesha stares you in the eyes lustfully. "Take off my pants." You unzip her pants and pull them down, revealing the smooth globes of her ass. You try to slip a hand into her bush, but she slaps it away. "Not yet," she teases.

You smile and nod. Neesha leans in and kisses you deeply, her tongue exploring your mouth, her long silky brown hair cascading around you. Her breasts press up against your chest, and you grab her bare ass in both hands, kneading and massaging. She raises her tits to your mouth and you happily suck at her hard nipples. "Oh God..." she murmurs under her breath, running a hand through your hair.

You lose track of time for a while, thoroughly enjoying letting Neesha be in complete control. Your other girlfriends were all too passive in bed, and you never realized how much being submissive would turn you on.

Neesha begins to squirm, obviously more horny than ever. She sits up and unzips your pants, letting loose your throbbing member. She lowers herself down, engulfing your cock with the lips of her pussy. With a moan, she begins to slide forward and back, and you can feel her hard clit rubbing across the sensitive head of your prick.

"Oh fuck!" Neesha cries out as she humps your cock. You respond with a loud groan. "Oh no you don't!" she barks. "You come when I say!" She looks serious, but her eyes are smiling. "Don't worry, baby," she gasps. "I'm almost there..."

She rubs herself with your cock, harder and faster, her hips crashing into yours. Suddenly her body jerks violently. "Ohhhhhhhh shit!" she screams, shuddering from the intense climax. Without warning she lifts up, letting your slick cock spring upright. With perfect aim, she drops down onto your hard rod. It slides fully into her wet pussy with no resistance as your bodies slap back together.

You gasp at the sudden tight embrace of her pussy, and at the feeling of her orgasm still pulsing through her strong vaginal walls. They grip and squeeze your cock, taking your breath away. "Holy fucking shit, Trent," Neesha says, her voice breathy with passion. She begins to bounce up and down on your dick, her smooth tunnel sliding up and down over you. "Your cock feels so goddamn good!"

You thrust your hips up to meet her wet snatch, aroused almost as much by her filthy mouth as by her tight pussy. The pair of you groan in pleasure, the sounds of flesh on flesh filling the room. You reach up and pinch both of Neesha's nipples, and she squeals with glee. You can feel your climax approaching fast. "Neesha, I'm getting real close," you say.

"It's ok," she replies with a loud moan, "so am I." She reaches down and starts to finger her clit as she rides your cock with renewed vigor.

You grip her hips tightly and force yourself deeper than ever into her as a powerful orgasm rips through you. Neesha screams out in ecstasy as she comes at the same time. Your tense bodies convulse together, wracked with pleasure. She collapses on top of you, breathing hard. Your cock and her pussy continue to twitch against each other as your breathing slows.

Neesha wraps her arms around you and snuggles into your chest, her head nestled under your chin. You run your hands across her smooth back and into her hair. You can both feel your cum leaking out of her around your cock. "Mmm, that was a nice injection, doctor. You sure filled me up."

You chuckle. "Yep, I've been saving that load up for a few weeks. Or maybe a few years."

"Shame," Neesha says. "I haven't gotten to swallow a nice big load of cum in a long time. Maybe sometime soon you could save up some more for me." You pull away from her and look at her in disbelief. "What?" she asks innocently. "I love sucking cock." She arches an eyebrow. "You gotta problem with that?"

You shake your head. "Goddamn, girl. You really are something else." She grins at you with a blinding smile and you know that your heart is lost to her forever.

"Well, thanks, Trent," she says, snuggling back up to you. "I'll take that as a compliment." Suddenly she pulls away again, looking concerned. "Did you really like it?" she asks in a worried voice.

"Like what?" you ask, confused.

"Me being... in charge," she says, biting her lip. "I really love being the dominant one, but most guys... don't like it."

"Neesha," you say, tenderly brushing her hair out of her face, "it excited me in ways I didn't think were possible."

Her eyes light up again in that way you have come to love. "Really?" she asks excitedly.

"Really," you reply reassuringly.

She hugs you tightly. "The world's been so fucked up for so long. Isn't it amazing we found each other?"

You stroke her hair lovingly. "I'm really glad we did, darling."

She sighs with pleasure. "Darling. I like that," she mumbles sleepily.

From downstairs, you hear a beep from the computer, indicating it has finished its analysis. "Hey, results are in," you say, "wanna go check them?"

"Nah," she says, holding you tighter. "It can wait. I don't want to take this lovely cock out just yet." She wriggles her hips, causing your spent manhood to stir slightly inside of her warm pussy.

"OK, darling," you whisper.

"Mmm," she replies, without opening her eyes. She plants a soft kiss on your neck. You respond with a kiss on her forehead. You pull the blanket up over her shoulders, and within minutes, you are both fast asleep. It is the best sleep either of you have had in years.