A dark night on a semi-barren planet. She sneaked out easily when she knew most would be asleep. She slithered quietly through the shadows and darkness. She remembered her calculations and knew this would be the only way, at least for start. She heard the cry in The River, knew her fate was sealed, knew it was akin to destiny, by all accounts it had already happened. Yet she was beyond destiny, beyond the River, one extra or one less move, one change in demeanor, one word or a thousand, and the future would change. She had no choice. She had thought about this before. It was either this girl or one of the crew, and she couldn't live with herself if she had to take from Mother and Captain Daddy. That's not to say she didn't think about it, that she didn't almost go through with it, but at the end, she controlled herself, her urges to be new and for self preservation.

This one though, she would owe her. She would be living on time bought to her. And she'd stop some takers from taking anymore. It was necessary, she kept repeating to herself. Of course, she could just have taken someone off the street that she would found the most useful, but for this experiment, this subject was deemed appropriate. What the Academy wanted from her, docility, yet strength, obedience, yet free thinking. Maybe if she could take those parts in her... maybe...

She stopped at the edge of the warehouse, just in time to hear the tidbits of information from the greater dialogue that she already knew would be discussed days ago.

"Look guys, they just sent me with the stuff. I wouldn't skim you or anything, you know that. I'm up to my elbows in shit as it is or I wouldn't be here at all, I'm just following orders." A nervous girl said, increasingly anxious. She was obviously over her head.

"Listen girly, deal was 50 crates, and I only see 40. The fact that they sent you means they know they skimmed us, so we's gonna have some fun with you now. Gotta send out a message, you know how it works."

Damn relatives, relative smugglers, promise to get me out of a jam and throwing me to the lions, sent me alone here... River listened to her thoughts. Of course, she knew all the details already. It didn't matter, and the girl would soon wish those were the last of her problems. But right now, she would be grateful.

River snuck in, and wasted no time taking out those from the shadow. They expected more people in the deal, and they were getting complacent. The ones from the shadows easily slumbered down at her sharp touch, while the others were relying on them for cover and not on themselves. Big mistake.

She appeared from behind them, the girl watching her fascinated. Maybe another hand? Or a... leisure woman for them? She saw her smirk and shake her head, as if answering her thoughts. Another of their guns? Couldn't be, was so small and frail... and she stopped, though she made no sound either way, and she fixed her with her gaze, and that smirk, almost mesmerizing. She had time to realize that yet, she was confirming it. Yes, she was a gun. Yes, she was dang-

Before the last thought could be formed, or any subsequent ones about the girl reading her mind, she took out a knife, jabbed it in one of the three men's back of the neck, took it out in a fluid motion, and did so similarly to the second before the third even heard the first hit the floor. By the time the third man turned around and raise his gun, he was hit in the kidneys, falling to his knees, at even ground with the girl. She had not moves except to dispose of the two in the second or two that it took, and her facial expression never changed. She put the knife in the front of his neck and pushed, and his hand moved from the gun to his neck, futility attempting to stop the blood flow. Of course, he didn't knew that what was important was already broken and cut, and there was no going back, but even if he was told so, it probably wouldn't have stopped his instinctive reaction. He fell to the floor, still gurgling.

In another fluid motion, one girl had the blood covered knife at the neck of the other, still smiling.

"Useful."

The other was in shock, but the word pulled her out of it. Useful. Yes, she was not useful to the others except in manners she didn't want to consider. And this girl had saved her life. Did she want the same... no, don't go there. No, she was told she was useful and she would act as such. She nodded desperately.

"Yes, yes. Useful. I can be useful. I'll be useful. Useful is my middle name."

River looked at her and nodded. Then, she pointed to the vehicles and told her to load the crates. Ah, a robbery, now the girl could understand. River just rolled her eyes, though the gesture was lost on the other. She could not see. It did not matter. Maybe it was for the best. She knew she could drive. Maybe on Earth-that-was, this was a discipline all acquired, but in the verse today, it was not known to all. She felt a possibility of her prize leaving with the useless stuff, so she already answered.

"A vehicle can accelerate to 100 kilometers per hour in 5 seconds. A knife only requires between 1 or 2 second to aim and launch. Accuracy is high to hit a vital point."

"Ok. Sure. Don't worry. Gonna get your merchandise to your base. Or boss. Or you're the boss... or... whatever you need. I'll behave. Just, no hurting, ok? I don't work well under pain, less good for both of us, right? Right?" She needed reassurances, but got none. The crates were finally loaded, although 2 more vehicles needed to be towed between the two of them to get all the cargo.

"Don't you have more crew to do this?"

"They do not know. Bring something useful for the girl. Excess load is redundant, but will please some."

"Solo mission. Great, just great." she muttered, hoping to not be heard. It was confirmed by a lack of reaction, though obviously River knew.

The mules carried slowly, but purposely towards Serenity through the darkness.

The next morning, the roar of mules woke up the crew. The had landed in a remote place of the desert planet, so as to not bring attraction. The deal was done, a run to the nearest town was made, and they were ready to take off. Mal hurried out of his cabin, meeting Zoe.

"Think those guys don't like the merchandise or the price?"

"I wouldn't see why they'd return in the morning. Night was a better time to strike, for any of our enemies."

The name of those enemies hung in the air. Could be Alliance, those searching for River, or others. They knew they weren't even safe in gorram space after that debacle with Early that almost turned into a catastrophe. Simon had been shot. Something had to be done soon, they couldn't stay on the defensive already. Serenity was their home, and to be invaded and subdued so easily reeked either of compliance or being over their head. Mal feared both.

So Mal did what he was used to do and took it like it came. He trusted Wash to be ready to take them out as soon as he gave the word, and indeed Jayne was in his skin shirt and short pants with Vera already pointing outside the ramp.

"OH GOD I DID NOT NEED TO SEE THAT! Gorramit, Jayne, put some clothes on..." he looked at the dust heading towards them "...after we deal with this."

"Permission to rip my eyes out, sir." Zoe answered.

"Come on girl, I wouldn't mind seein' ya in something like this from time to time, even iffen it were an emergency" Jayne answered with a leer.

"Permission denied. And you shut it, Jayne."

As the dust cloud approached, they could see the silhouette of someone... a small someone in what appeared to be a bluish nightgown...

"Gorramit, it's River. Anyone know why and when she left last night?"

"Are you really asking how she could have sneaked passed us?" Zoe deadpanned.

"Point taken, but it smells like trouble. At least she came back. After those last talks, I'm glad that if she actually left, she's decided she's not better off without us. Who's she with, anyway? Kinda looks like Kaylee, but she's not dumb enough... TELL ME she's not dumb enough to take my fragile easily shootable mechanic in the middle of the desert!" Mal almost snarled.

"Kaylee? Where you at, girl?" Zoe asked over the comm.

"Ugh... Wash got on internal comm and woke me just now... heading to the engine now, just in case... what's going on?" she answered.

"So you're inside the ship?" Mal asked incredulously.

"Where else would I be?" she replied groggily.

"Then I think River's coming in with a twin o' yours."

"Twin? I don't have a twin. Shiny." Mal almost slapped himself.

Mal closed the comm. "Well, let's see what problems she bringing this time."

Finally the two arrived, and what was more striking were the crates on the mules, and that there were 4 mules, not 2. Good enough for an ambush, and Mal and Zoe's instincts kept expecting people to pop out from the mules and start shooting, but River wouldn't do that to them, would she? Then again, she did have her... episodes and maybe could be persuaded?

River rolled her eyes and looked at them with a bored look. "Serenity is safe."

"What's in the crates, Bit?" Malcolm asked, without bothering to lay it on her for leaving alone and risking her life. He figured, if she arrived well, risk was worth it. River mentally nodded and smiled to the compliment, though she gave no sign.

"Weapons."

The other girl almost blanched, and so drew attention on her. Three eyes were studying this Kaylee-clone, though there were some differences. The red-brown curly hair was the one that most resembled Kaylee, as well as her height and outward appearance, but her face looked rather plain.

"And who's your new friend?" Mal asked.

"Charlotte. Charlie to friends." She thought she got a look. "But you can call me Charlie. Sure. I'm Charlie, nice to meet ya all." She put up the best grin she could, though she was freaked on the inside. Weapons? She'd been tricked in riding with 40 crates of weapons, and to take the fall for 10 missing? Now she understood why they were so eager to make an example out of her, and she knew it would have been a nasty time for her, that was for sure. Deep inside, she felt that human life was priceless, but she knew here on the Rim the price of a life and it was cheap. Unless you had skills. Unless you were...

"Useful." River smiled at her, a much warmer smile than in the werehouse, and nodded. Mal looked awkwardly at her, but she ignored him. Jayne however was already heading to the crates, and when he opened one, he looked like a kid at a candy store.

"Holy balls, girl, you got taste in firepower. Semi-automatic, automatic, and enough ammo to shoot a day, and that's only in one of these them crates!"

She kept up her smile, but Malcolm was troubled.

"And... where did you get these? And why? How much we owe and to who? I don't like to leave debts unpayed." She didn't want to give too much. Maybe he'd understand that she did this because she couldn't do it to her crew, her friends, her family, but maybe he wouldn't. He was the Captain and her superior officer, and if he'd tell the others to accept it, they would, but if he didn't... well, she couldn't spoil it before she could even test her theory.

"Already been payed for." She said in a musical tone. "The takers will not take anymore. They have been swallowed by the tide of history and memory."

Mal put the pieces together immediately. Ah, she sighed, if she could pull her own together so easily and so fast. "You took out an entire crew?" The other two were speechless.

"Yep, your girl's one tough one, I gotta say. Never saw men fall so fast. No idea why the snipers didn't fire, I mean, there should have been some there, right?" Charlie put in, who had been a first hand witness of the transaction. She couldn't understand why they were so surprised at her, the girlish demeanor may have fooled anyone not knowing her, but she thought these people had been on the same ship for enough time to know her worth.

Malcolm turned slowly to River. "That true, girl?"

"Necessary." River shrugged, caught Charlie by the hand, and ran with her into Serenity. Mal swore strongly, then turned to his gun.

"Jayne, get these crates inside, you can admire them all you want when's we in the black. I can't take the chance someone's chasing, whatever Riv says. Come on Zoe, let's give 'em a hand."

Back in the ship, River was running and dragging Charlie by the hand, laughing and ducking like a little girl playing. Charlie tried and barely managed to keep up, lest her hand were pulled out of her socket. She knew this girl was not what she seemed, and that she shouldn't upset her. But she had started to develop a small suspicion. Her way of talking, her behavior... she knew gun hands weren't all that right in the head, but she knew... functional ones. This one seemed... problemed though. She tried to keep her thoughts focused and using words in her mind that wouldn't offend, because her subconscious was telling her something a lot more farfetched was going on here.

"Close." The girl answered. She took one more corridor, stopped, looked at her and smiled sweetly. "She's smart." She opened a hatch to a cabin and shoved her in, then locked the door. "Brain patterns are similar enough to be able to give without permanent and unwanted scars. Less intelligence would make the girls incompatible. Yes, she is useful." And then River left, leaving a scared girl locked in Serenity's guts, incidentally just next to her own bunk.

Disclaimer: I do not own any characters, and I do not profit from this story.

Author's Note: So I read some of the more reviewed fanfic of these two fandoms, and a few things bothered me: that the Necromongers and other things didn't appear, that the stories were often hijacked by River and Serenity and Riddick was just a tag-along passenger/gun/love interest to River, and that I had to read the same lines from Firefly in a very, very little different context in most of them far too often, and from this I think I'm going to remember some of those lines forever (and I still don't know if it's a good thing or a bad thing). I am definitely not going to rewrite the entire Firefly season again, so I'm putting this between the 13th episode of Firefly, and a few months since Riddick left Jack (but not long enough for Jack to have decided to follow him, yet).

Edit: I apologize for the rant above, if only on the issue that I actually read recently a story that uses the Necros interestingly, and that my own seems centered around River and the Serenity itself. That will change in time, but things need to be set. I have also noticed now, while writing this story, why Riddick has only around 10% (irony much?) "screen time" when "paired" with Serenity: there are a lot of characters on Serenity, and ignoring them is something we shouldn't/can't do. Giving Riddick 50% of the presentation may be a mistake if I follow through, too. Unfortunately (or fortunately, depending on your interpretation), this will make the story much longer and take much more to tell if I'll hickup in every character, and although I hope you enjoy the side stories and talks and POVs, they will still be, in my interpretation, filler.

I am also going to go in a different way than the "contract" (I'd appreciate if someone would tell me if this is canon or fandom). The glowing blue is still canon (of sorts) and so will be used, but in this story, the reason for the connection between River and Riddick will be different, and initiated in a different way.

Rated T for language, violence and other possible future events.