Disclaimer: I claim no rights to Yu Yu Hakusho, nor any related characters or merchandise, and I make no profit from the writing or distribution of this work of fiction.

The Apocalypse, when it comes, is rather anticlimactic. There are no devastating earthquakes, no showers of fire and brimstone, no epic battle between good and evil. Only a gentle sigh as people all over the world breathe their last and simply fade from existence. And in the end, the people who survive have very little in common apart from the fact that they are unexpectedly alive in a very different world from the one they knew. In the end, no one group is spared: not the deeply spiritual, not the survivalists, not the weak nor the strong. Families and friends are torn apart, but what else can you expect from the end of days?

Yusuke is taken in this mass disappearance, and each of the others has his own opinion as to why. Kuwabara is willing to chalk it up to random selection. Kurama is fairly certain that it was a conscious decision on the part of the Reikai, but isn't prepared to venture a guess about the reasons behind it. Hiei, on the other hand, is almost positive that the Reikai has taken the Detective as a preventative measure. He still hasn't forgotten how desperately Reikai forces fought to eliminate Yusuke during the Sensui incident. It's not unlikely that they have now seized the opportunity to deal with him once and for all.

Regardless, the remaining Tantei work together in the new world, looking out for one another, and for a time, everything is all right. People are content to keep surviving, living off resources that are suddenly plentiful. The inherent need of some for conflict leads to the occasional small altercation or brief riot, but for the most part, time flows smoothly on.

And then the fog comes. "Fog" is really a very loose term for it, as the only resemblance it bears to the real thing is that it rolls in off the water. Any water. Lakes, rivers, streams, puddles: they're all fair game. And it takes advantage of all of them, rolling steadily onward, consuming everything in its path. Rarely does it retreat, but when it does, it leaves nothing behind.

It's not as though the fog leaves devastation in its wake, or takes the living things, or the buildings, or both. It takes everything, leaving disconcerting spaces of…nothing. Spaces that make you feel as if you've gone blind, simply because there is nothing that exists there to see.

The Tantei lose another to the fog. Driven to madness by the sight of his family – miraculously spared during the mass disappearance – being enveloped by the fog with howls of agony, he commits suicide. The last two do the only thing they can: they move on, careful to keep a safe distance ahead of the drifting fog.

Fear grips what little population is left, driving them to ever-greater acts of violence, but the Tantei are capable of protecting themselves. For the most part, they simply avoid the conflicts, sticking to sparsely populated areas when they can. And as they move steadily inland, they try not to think about the fact that unless something changes, there will soon be no safe places left to go.

******

Though he doesn't move until he feels Hiei lightly grasp his shoulder, he's been awake since the fire-demon first shifted. The time since the Apocalypse has changed him, made him that much more aware of his surroundings, so that when Hiei touches him, he sits up immediately, brushing his hair out of his eyes. That's another thing time has affected, but he has more important things to worry about than the steady lengthening of his hair. Like staying alive.

"Watch change," he hears Hiei state simply as the fire-demon moves around to the other side of the small campfire. He makes a small noise of acknowledgement, pulling his bright hair back into a ponytail.

"Anything?" he asks, knowing that Hiei will understand, and glances up in time to see Hiei nod briefly.

"When do we move?"

"Soon," Hiei replies, his unease conveyed only by a minute dilation of his pupils as he gazes absently into the fire. It's enough, though. With all the time they've spent together, words are hardly necessary anymore. They rarely speak (not that they did much before, either), preferring instead to simply read the subtle body cues of the other. "Wake me at dawn."

He nods once more, and turns away. Hiei sleeps, and Kuwabara takes the watch.

******

He's late waking Hiei up, and he knows the fire-demon knows when he finds himself on the receiving end of a 'what-the-hell-were-you-thinking' glare. Kuwabara only shrugs it off and shoulders the pack, tossing a bag of jerky across the remains of the fire.

"You packed?" Hiei asks, the glare softening into something akin to surprise. Kuwabara just shrugs again.

"You said we needed to move."

Hiei says nothing more, only gazes at him for a moment before nodding – in appreciation, Kuwabara would like to think – and heading off, Kuwabara trailing close behind.

In actual fact, Kuwabara packed up camp for more selfish reasons: he wants to move. He's felt the fog creeping in all night, and he's more than ready to run. Even if he hadn't seen firsthand what it can do to people – hadn't been made to watch how it turned Kurama into an empty husk, unable to use his powers, mere deadweight until the day he killed himself – he'd still be deathly afraid of it for the sole reason that it is one of the few things Hiei fears. Kuwabara has witnessed the fire-demon take on monsters several times his size, seen him rush headlong into deadly situations, but Hiei runs from the fog. That fact alone is more than enough to put Kuwabara on high alert.

They move quickly but cautiously – as they always have – relying on Hiei's Jagan and Kuwabara's intuition to keep them out of danger. Generally, it's enough, and they veer around trouble spots with little effort. But there are days it doesn't work quite so well. Days like today.

There was a time, not so long ago, when Kuwabara would have ripped into Hiei for daring to shove him abruptly backwards by planting a firm hand in the center of his chest. But things have changed. Now, he merely catches himself and remains outside of the clearing Hiei has stepped into. He can't feel anything amiss, but he trusts Hiei (and no matter how long it's been, that feeling is still a little foreign) has a good reason for wanting him to stay away.

He catches the brief rumble of voices before a childish whimper of fear drifts to his ears, and he knows. He knows what they've stumbled into, because they've seen it before: a slave ring. Groups of men who have taken advantage of the pervading fear to round up stray women and children and force them to follow orders: orders ranging from hard labor to sex.

The hiss of sharpened steel cuts his musings abruptly short. The women scream, the children cry, and Hiei calls for him. He moves carefully into the clearing, registering Hiei's nod of acknowledgement in a far corner of his mind. He doesn't need any explanation: it's always like this. Hiei's just not good with people. That's one thing that hasn't changed.

Slowly, he approaches the huddled group of women and children, noting that they have fallen slightly behind one woman. He kneels before her, noting the way she shrinks away.

"It's all right," he murmurs gently, and the pang that goes through him is not unexpected. He approaches these broken women the way Yukina used to approach skittish animals, or those wounded and frightened. The thought makes him ache. "Everything's going to be all right."

The dark-haired woman at the front stirs slightly. "Killed them," Kuwabara hears her mutter. "Killed them all."

Assuming she is talking about Hiei, Kuwabara risks a quick glance over his shoulder to where the fire-demon is cleaning his blade. If the comment bothers Hiei, he gives no sign at all. "Hiei? Yeah, he'll do that. But he won't hurt you, I promise. We just want to help."

Kuwabara reaches out, trying to see past the fall of hair into the woman's downcast eyes. Slowly, she raises her gaze, and Kuwabara knows he's made a deadly miscalculation. As her eyes flare dangerously, her hand lashes out.

He can't move quickly enough; her ragged nails tear bloody lines into his cheek, and the contact forces Kuwabara's intuition. Images, emotions, sensations, flood his mind, and he reels, falling to his knees.

The woman lunges for him again, but Hiei gets there first, his katana flashing with deadly precision. Blood arcs in a fine mist, and that's just too much. Kuwabara's stomach heaves, and he leans over and vomits, shaking violently as he is forced to live the sad existence of this woman: captive, used, tormented, kept in constant submission by the fear that she will be the next chosen as a sacrifice to the all-consuming fog. And through it all, Kuwabara still manages to be grateful that he cannot hear the screaming over the sound of his own retching, or smell the blood over the acrid stench of bile.

Long after the memories have faded, and Hiei has killed the last of the women gone mad with grief and fear, Kuwabara remains on his hands and knees, dreading the moment he has to look up. After so long, he doesn't think he can stand the sight of Hiei's condescending gaze.

He hears footsteps approach, sees small black boots enter his field of vision, and curses inwardly. But Hiei only stands there silently, and when Kuwabara does steel himself and glance up, the fire-demon has a hand outstretched and an odd look in his eye – one that Kuwabara can't put a name to, even after all this time. But it's not anger, and it's not exasperation, and it's not disgust, so Kuwabara reaches up to grasp Hiei's small hand. The fire-demon helps him to his feet without a word, and they set off once again.

Neither ever lets go of the other.

******

That night is…different. No one takes the watch. For a moment, Kuwabara considers mentioning this, but he figures they've come a good distance today: he can no longer feel the fog's oppressive presence in his mind. Slowly, he relaxes, welcoming a night that can be spent without fear, for the first time in a long time.

It is probably this long-awaited relaxation that keeps him from protesting when Hiei curls up close to him. And it is probably this relaxation that prompts him to wrap an arm around the fire-demon. And it is probably this relaxation that finds him pulling his one-time annoyance into a warm kiss.

It's slow and kind and dizzying, and Kuwabara loses track of himself until Hiei is astride him, and he's thrusting gently upwards into that tight heat. And it's strange, so strange, because he's fairly certain it's not his red hair that Hiei's running gentle fingers through, just like he's pretty sure Hiei knows that Kuwabara's seeing another petite red-eyed demon above him. They make love, not to each other, but to those they have lost, and the sleep that claims them afterwards is deep and peaceful.

******

Kuwabara wakes drenched in cold sweat, breath rasping in his throat as the fog batters at his mind. He doesn't need to look around, but he can't resist the sick urge, and his sight only confirms his mind's sense of impending doom.

He is sitting in clear space about ten feet in diameter, cut off from the rest of the world by a wall of dense fog. Hiei stands calmly about four feet away from the mist, one hand resting lightly on the hilt of his katana. He hasn't shown the slightest reflection of Kuwabara's panic, and suddenly, Kuwabara understands why.

"You knew," he accuses softly, and the minute tense of the muscles across Hiei's back tells him everything he needs to know. Well, almost everything. He doesn't know why he didn't know, as his natural precognition has always been more reliable than Hiei's acquired Jagan…

Then Hiei glances back at him, and his face is open, his expression vulnerable for a brief instant, and Kuwabara reads every emotion in his eyes: pain, loss, resignation, guilt, and a thousand more before the fire-demon brings himself back under control.

"Bastard," Kuwabara murmurs, but there is no heat behind the curse. "You've been blocking me, haven't you? That's why I couldn't feel it. That's why we ran into those slavers yesterday."

"Yes," Hiei answers simply, and returns to his contemplation of the fog.

"Why?" Kuwabara asks. He's not expecting an answer at all, much less the one he gets.

"What good would it have done for you to know?" Hiei says with a shrug. "What could you have done?"

Anger flares in Kuwabara, and he embraces it gladly, if only as a momentary respite from the mist's draining presence. "Anything!" he shouts furiously, voice cracking from the force. "We could have run! We could have lived one more day!"

Hiei's gaze snaps back to him, and for a moment, he is once again the belligerent demon Kuwabara could not stand. "We live on an island, you idiot," he retorts, eyes blazing. "It was bound to happen eventually."

Suddenly, his gaze goes blank again, the fire dying just as suddenly as it kindled. "It was bound to happen," he repeats softly, turning away for good.

Kuwabara fights to stay angry, struggling desperately against the desire to let his emotions drain away from him, to let the fog take his very being. "That just sounds like a bullshit excuse for you to give up." He hardly knows what he's saying. All he's doing is trying to feed the anger. "But you've never really wanted to live, have you? You gave up the day Kurama died." He stops abruptly, knowing instinctively that he's crossed an unspoken line.

But Hiei only nods slowly. "Yes," he muses. Kuwabara's not sure that the fire-demon is even aware that he is speaking aloud. "Maybe you're right. But it doesn't matter now. Whatever lies beyond this fog, that is where everyone has gone. And that is where I go now." Before Kuwabara can even consider reaching out to stop him, Hiei walks briskly into the fog without a backwards glance.

And just like that, Kuwabara is alone: the last of his friends, the last of his family, the last of his team, perhaps the last of his race. He feels a fleeting moment of panic as the fog rolls steadily closer, but emotions seem so unnecessary now. With only a token effort at resistance, he lets the mist sap his thoughts away and watches impassively as his world fades to white. His last thought, which comes to him through a haze of fog, is the faint hope that Hiei is right – that he will be able to find everyone again on the other side of the mist.

And then he knows no more.