For the Dead Travel Fast

—-xxx—-

"That's actually our best bet right now."

Kate stared at the doctor from the floor of Castle's room. It took her a moment to find words. "You cannot be serious."

"It's a viable option." Doctor Harris moved to the hospital bed and hopped up, so tall her feet easily touched the floor. She carried an iPad in her arms and looked statuesque, like a goddess from a frieze had come alive. "I went looking through our extensively typed and screened blood bank, and we just don't have anything quite like yours."

"See?" Castle hissed. "You need it."

"I don't need it. Right, Dr Harris? I'll still heal but more slowly without—"

"I'd say we're dipping towards need," Harris interrupted. She held up the iPad, turning it around with a flourish to show off some kind of chart. "Your blood sugar is 67, which we consider low and in need of remediation. Plus look at your iron levels—far too high. From what I can tell by the reactions in my lab, your algaic component in your VL-load isn't producing as well as it should. It's likely you inadvertently hit on this in an effort to control the bloodlust, especially once you were in sexual relationships in which you didn't tap a vein."

Kate flinched.

"See?" Castle hissed again. "You've been suppressing your natural instincts, which are there for a reason, Beckett. Now you're all out of whack."

"Nothing was being suppressed," she growled.

"You ever get the urge to bite him?" Harris asked.

"Oh, she definitely does."

"Castle," she snapped.

"Does she draw blood?"

"You mean in sex or in general?"

"Either."

"Sometimes in—"

"Castle," she muttered, mortification hard to carry when she was so damn tired. "I'm not sure this is—"

"It's relevant," Harris interrupted. It was like being interrogated by a Yoruban orisha, cosmic, epic, slightly bewildering. "For those who carry a high enough Lichen Load in their systems—or vampires, for lack of a better word—sex is the natural way we build energy networks, share resources, and swap immunities. With something as simple as a lick of the tongue or as complex as a letting."

"So vampires are the original swingers," Castle joked.

"No." Harris gave him a flat judgmental look. "Not at all. Surefire way to get ourselves killed."

Kate elbowed his ribs to get him to shut up for once. "Because of the antibodies—I mean antigens, right? In the blood."

"Yes, exactly." Dr Harris had another hard look for Castle before she went on. "As I was telling you earlier, you wouldn't transfuse an ER patient with AB blood because in all likelihood, the victim has those antibodies and would reject the transfusion."

"In the emergency room, don't they give all incoming trauma patients O negative? The bleeders I mean," Castle said. "Because it's safest, universal donor."

"That is true," Harris said cautiously. "Though it's different with plasma." She looked suspiciously at Castle. "I see you know some about blood."

"Oh, not like that," he said hastily. He cleared his throat with that nervousness he got for women in authority. "Research for books. And an unfortunate experience with a gunshot victim a few years back."

There was a beat of silence. Kate squeezed his knee. They were still crumpled against the clear glass wall, wedged into the corner like wounded animals.

"That was me," Kate spoke up. "He's talking about when I was shot." She sighed. "The first time, at my Captain's funeral."

Some of the askance cleared from Harris's face and she nodded, still intently studying them. Kate figured the woman had two or three syringes on her which she could use against Castle should it come to that; she wouldn't put it past the woman to do it for no reason other than not liking Castle's smell. Or hers.

Though, to her, Castle smelled rich and indulgent and wonderful. Every inhale settled her a bit more, gave her a certainty that it was going to be just fine. Whatever her injuries, whatever she'd done to them when she'd started his transition, they were together.

That's what his body told her. She hoped her body told him the same. They did this together.

"She still smells a bit off," Castle spoke up. "And no, I don't know anything about lichen, but I guess it has a smell. Fishy? Like seaweed."

"She smells off to you?" Harris asked, interest piqued. "Really? Seaweed, huh. Maybe that's the algae component. That is... most fascinating." She flipped through something on the iPad and came to a chart, showed it to them. "Have any idea what these numbers mean in relation to that seaweed smell?"

They looked at the screen then at each other.

"No," Kate said, almost nasty with it. She was tired of being treated like a reckless moron, though she supposed, to Harris, she was. She'd turned her husband without even knowing basic, elemental truths about what it was she was doing to him. "Sorry, I'm tired, and irritable. No, we don't have any idea about the medical side of things. No one ever bothered to enlighten me, and I don't have it to give to him. Anything you can tell us, help us with... we'd appreciate." If she sounded grudging, she'd have to work on that.

"And I can appreciate where you're coming from. Here's what I propose: a symbiotic relationship of our own, in which I give you all the medical knowledge and understanding you lack, and you provide me data."

Castle perked up. "That would be really—"

"You want to experiment on us," Kate said baldly.

There was just enough hesitation on Harris's face to send Castle to his feet. "Hard pass," he growled.

Harris stood from the bed as well, tucking the iPad against her hip. "No, no, not on you. I just want a few vials of your blood and regular contact. A chance to run tests over time."

Kate couldn't push herself upright, but Castle was doing the guard dog routine handily. "Run tests," he said icily.

"It would be a two-way street. A symbiosis, remember? I help you, you help me. When you're through all the phases, and it's safe for you two to go back to your lives, you're gonna need the Horde community, even if you don't want it. And this way, you'll get as small a connection as possible—just me."

Castle glanced at her. There was so much begging in his eyes, she had to close her own.

"Why is it you're so interested in us?" Kate said. When she opened her eyes to face the woman, she recognized something in Harris she hadn't ever seen in another person before—

obsession.

It was the same fierceness to succeed and unwillingness to listen to the wisdom of others that Kate had seen on her own damn face. Looking right back at her.

She should say no. That kind of crusade was scary, was bound to ruin them. Hadn't it brought her here in the first place, shot up and dying and forced to make her husband into a monster?

"You two have something of a closed system, a new form of the VL, a rapidly-mutating mutualism that responds favorably to codependency. As far as I know, there are none like you, the pair you make. The need you have for each other. I put you in this room with him and within ten minutes he's through one of the worst and most deadly phases—it's unheard of. Most deaths from VL are incurred during that phase, and he came right out of it, on track, like it was a day at the damn beach."

"Sweating like it, anyway," Castle piped up. "Get me some sunblock, Doc."

Kate wished he didn't sound so willing to be experimented on, but that was Castle. Always the optimist.

Harris spread her hands in a gesture of submission that Kate didn't believe for a second. "What you can teach me... about ourselves, about this symbiosis—just the fact that he can smell that your algaic levels are off, it's crazy." Harris gave a helpless shrug, her face shuttering, hard once more. "Besides. You need to know what you're getting into. You need me."

If Kate had the energy, she'd argue Harris down. She'd stand up and walk out of here.

But instead, she heard Castle say you've got a deal, even as her consciousness was sliding away.

—-xxx—-