NOTE: This is my first Shingeki no Kyojin fanfic and I've only watched episodes and fanarts, but honestly, I think I did okay. A line stolen from BBC's Sherlock.

This is the real goodbye. Or, Rivaille and Eren learn how to live.

The boy talks to him before the world collapses. Of course that would suggest the world wasn't already in ruins and complete shit, but semantics. The world collapses and takes everyone with it. Well mostly everyone, there is still the brat. There is still Rivaille, but he doesn't count, not really. He's always lucky, apparently, or unlucky. It depends on the way you tilt your head to look at it.

The brat, Eren, cries for Mikasa, for Armin, for everyone and everything, and Rivaille guesses he can do it for the both of them. He remembers Eren looking up, tears and blood streaking his face (Rivaille cannot complain, not right now) and chuckle half-heartedly at Rivaille's expression.

"Forgive me, Corporal, I can't be as collected as you."

Rivaille says nothing.

They get up, and they move.

"It's funny," Eren speaks up, "I've always wanted to see the outside world." He does not look back to see Rivaille's expression. It doesn't matter now.

"But it's not as appealing anymore," Eren finishes. Death does that to you.

He's surprised Eren just got that.

Rivaille is tired of Eren's consistent complaining. Granted, it's for a valid reason, but Rivaille has to deal with filthiness and death too, but he learns how to take care of it, how to cope, even if it's only superficial.

"Stop whining," Rivaille says, and wipes the blood off his blades carefully. "Do you expect to exterminate all the Titans like that?"

Eren blinks, before a reluctant smile takes up his face.

"I guess not."

Rivaille's only a little relieved when there's a little more jump to Eren's movements, an anger, some motivation instead of the dead weight.

The first time Eren's Titan goes completely ballistic is the last time Eren transforms on purpose.

Rivaille remembers almost being crushed. He had looked back in shock and anger at Eren, who was raising his hand again, and he shouted, "Get your shit together, Jaegar!" Rivaille did not expect it. No matter what reservations everyone had of Eren's Titan form, he had gotten used to Eren's loyalty, his steadfastness, and now everything was going wrong again.

Something clicks in Eren's expression before the Titan form collapses.

Later, when the fire is cracking and Rivaille is cleaning his blades almost obsessively, Eren speaks up.

"I'm sorry."

Rivaille falters to show he was listening, before continuing.

"I- usually, it's only the Titans. And you're definitely not, height and all, so there's no way I could have mistaken you for one."

Eren flinches at Rivaille's glare, and backtracks.

"I mean, your stature as a human, not your abnormal shortness, haha- crap."

They both forget about the Titan form, or willfully ignore it.

The second time, Rivaille sees it coming. The second time, Eren does too.

"I can't do this anymore," Eren says, and Rivaille listens with half-hooded eyes.

"I'm going to kill you one day, Rivaille," (ah, there is his name, he forgets when he gave Eren permission to use it), "and you can't let that happen."

"Hm," Rivaille answers, "I don't need your reminder."

"Of course," Eren says, and looks away. The boy seems to collect himself, before leaning over and pressing his lips almost chastely against Rivaille's. Eren leans back quickly enough, and grins nervously.

"Just to understand," Eren says, and Rivaille simply leans in for a more pressing kiss, hand fisted in the other's hair.

When Rivaille leans back, there is a hint of a smile gracing his face. "Just to explain."

Eren blushes, and laughs. It's nice.

The words come unbidden out of Eren's mouth and into Rivaille's one night.

"You have to kill me," Eren whispers against Rivaille's lips. Talk about a turn-off. Rivaille frowns, and Eren leans back.

He grasps Rivaille's hand in his own, wraps it around his throat. "When it comes, you have to kill. Promise me."

Rivaille frowns, pulls away. "I didn't know you were so sick of me you wanted to die that much."

"No," Eren says, and pulls Rivaille back, eyes intent on the older man's. "No, you have to listen to me. I-" Hesitation.

"I love you," Eren says and Rivaille looks surprised. "And I can't stand the thought of hurting you. I'd off myself, and that'd just be pointless, wouldn't it? You still have a chance without me, Rivaille, you can still live. There's still some civilization out there."

"Tch," Rivaille retorts, annoyed and angry, ripping his hand from Eren's and glaring. "You're a coward, Jaeger, you're too much of a coward to deal with another death and so you shove it on me. You're so scared of dealing that you want to die."

Eren looks angry, but seems to calm himself (a feat that is usually in Rivaille's possession).

"Of course I don't want to die Corporal. No one does, not really. But I don't want you to die either, so I guess I'll have to compromise."

"Besides, you don't love me. Not like I love you anyways."

"What are you to say what I do or do not love?" Rivaille retorts, trying to collect some anger, some spark in his tone, in his body, but it has dulled.

Eren laughs. "Your lover," and kisses Rivaille. He takes a moment to return it. (Eren is wrong, of course, as he is prone to be but he does not need to know).

"Promise," Eren demands, lips pressed against his hungrily.

Rivaille hesitates.

"I promise."

It feels like a goodbye.

The air drapes over him comfortingly, a silent encouragement, a quick push above and Rivaille is taking a deep breath of fresh air, barely a hint of blood in his lungs, and the sun bleeds in his eyes. It is almost like time has dulled for a moment, but he doesn't dare close his eyes. The 3d maneuver gear swings him around, the wind roars and sometimes he wishes he wasn't Mankind's strongest soldier, even when he promised he would be.

Because his promises are a part of him, and he was supposed to exterminate all the Titans, for everyone who died and everyone who would. But, he glances at Eren, at the Titan's back and hesitates slightly, only slight, but that is the single second that will send a house of cards tumbling down and crush sand castles (not that he knows what they are, metaphors weren't made for understanding). There is no room for hesitation. But, here he is, heart climbing up his throat and the blood of every promise on his blade, and Eren's turning to look at him with a sword stuck in his throat.

It would be easier if Rivaille could say there was no resemblance of Eren in this Titan's features, no nervous expression, no slight smile, no earnest determination in its eyes. It would be easier to lie. But this life was not built for easy things, and Rivaille can see that not all Eren is gone, though he can't control it. Perhaps Eren and this Titan were one and the same, even if the thought is abhorrent.

Eren is glancing up at him, and everything in the world shatters into broken pieces of life.

Except, not really, that's just Rivaille, because this isn't what he wants, isn't what he needs to do, there will always be somewhere else, some when else, and he doesn't understand why they can't try again (but he does, and he will), and it'll be hard without the brat, no matter what he says and does and Eren knows this, he understands this better than Rivaille does himself, so why why why-

All this is fathomed into thoughts in seconds, more seconds that Rivaille wants back to memorize Eren's face, Titan or not, and the Titan has a flash in his eyes, something like acknowledgment, something like acceptance- but Rivaille is lying to himself again.

Because that is not acceptance, that is not acknowledgment, that is fear. Because no one wants to die, but they do, and they will. But this life is built for harsh things and dying is one of them. Eren looks at him and it feels like Death has gripped him by the heart and said, "This is your heart and you should never let it rule your head." (Maybe it isn't the Titans he's trying to destroy).

"Of course I don't want to die Corporal. No one does, not really. But I don't want you to die either, so I guess I'll have to compromise."

This is the real goodbye: a blade against the throat, quick and silent.