Disclaimer: I don't own any of the characters from Twilight OR CoR, sadly.

A/N: This is a crossover, but I am posting it here in the hope that more Riddick fans will find it.

I see a lot of connections between Twilight and CoR, and think the characters will get along great. But I want the story to be fairly serious, and I'm still trying to see if a serious crossover is possible. We'll just see where this goes! Suggestions are appreciated!

Chapter One. A bargain.

"Is it possible?"

"It hasn't been done," Aereon replied. "No Necromonger who has reached the Underverse would wish to return. No live Necromonger would try to retrieve a brother who has passed on. It is against all they stand for. And then there is the matter of the body." She stood at the foot of Riddick's throne, no longer a captive but a willing consultant. Negotiater. She seemed to still hope Riddick would put an end to the Necromongers and their crusade, and not kill her in the process.

"Zhylaw went there and back. Now it's my turn."

"Your predecessor was a Necromonger, and so was able to pass into the Underverse unharmed. Trying to do so would kill you, unless you first converted."

He snorted. "No thanks." Aereon was continuing to annoy him. He was pretty sure he could kill her, immaterial being or not. It couldn't be much different from killing Zhylaw. "So I'll send someone in after her. They have to do what I say now."

"If I were you…" Aereon walked, or drifted or whatever, closer. "I would not give any further sign that the girl is important to you. And I would not put her in the hands of a Necromonger. There are ambitious ones among them, who think they should rightfully be Lord Marshal. They might follow your example."

Restless, he threw a shiv, slicing another spike off the pillar that had killed Kyra. It was his favorite target. For some reason he had not had it removed. He figured it was what she would have wanted, a monument. Maybe he just liked the smell of her blood. "Who can do it?" he asked.

"No one that we know of."

He spoke low. "Start thinkin' of reasons I'd want to keep you around."

"Before you kill me, Riddick, think of what is at stake. You rule the Necromongers; you can allow them to continue their war, or put a stop to it. As of now, the universe is tilted, weighted toward Death, and sooner or later everything will fall into its maw."

Riddick stood to leave. He didn't mind the idea of burning another world, converting or killing everyone on it. Or both, like what had happened to Kyra. "If I don't get her back, the universe can go to hell as far as I'm concerned. It had to end sometime. And so do you."

"And if you do get her back?"

"Then I'll put an end to this Necro business like you all want."

Aereon picked up a strange pendant hanging around her neck. It appeared to be a large black opal; the flecks within glowed and danced like galaxies. She gazed into it, then looked up. "I know of… people who may be able to help you. Not in this universe, but in one similar to our own. People of a peculiar race: they are dead, but walk among the living. They were once human, but they have their own bargain with Death."

"How do I find them?"

"We elementals can see through to the other universe. On occasion we have gone through ourselves. We can probably forge a bridge for you. The planet is where Old Earth would be."

"And you say they're dead but still walking around."

"Yes, they exist in a younger universe where things went differently. Immortals with almost no vulnerability, with strength and speed and senses greater than any living being. I am speaking of a very powerful family in particular, one with extraordinary abilities. They could easily defy you. But they have an even more powerful enemy posing a threat. Perhaps you could be of service to them as well."

He rumbled. "So I'm supposed to go ask for their help?" But it didn't sound so bad: kill the bad guy no one else could, get something in return. He'd just done a job like that, actually.

"I would try asking before your usual approach."

"And you think they wouldn't mind stepping out of their universe to go to this place called the Underverse, which may or may not kill them because they're not Necros."

"They're already dead. It's our theory that they are compatible with the Underverse."

"Your theory. What are the odds that it will work?"

She smiled. "The odds are good."

"And the body?"

Still smiling. "If necessary, they can help you with that as well."

"Good. Get me through."

End Chapter One.

Coming up next: I have the conversation between Bella and Riddick finished, I'm just trying to flesh out how Riddick gets there. Should be fun!