For the Dead Travel Fast
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Castle made a face in sympathy as she drank the noxious milkshake, but he tapped the bottom of the glass, tipping the onion-and-garlic concoction down her throat when she blanched and tried to pull back.
She gagged a little. He made more sympathetic noises but she gave him a death glare that stopped him cold.
Well, stopped him hot. He was burning with an unnatural fire inside, and this was the way to cool the flame. All Kate had to do was drink from him. Or so Dr Harris claimed.
Castle believed her. But he also believed Kate's lived experiences when it came to being in transition. The two sounded mutually exclusive on the outside, but he was betting that a thousand years of vampire lore and a Horde that organized around peacemakers couldn't be that far off about it.
Sure, there were bad guys and good guys, but weren't there always bad guys and good guys? Vampire bad guys just happened to have a bit more agility and speed, not to mention a jaw strength to rival a shark. (Around 4,000 psi, estimated.)
Kate choked down the last of the garlic-and-onion milkshake.
Meanwhile, Dr Harris mixed up a second batch, this time for him, while she explained the prion disease ravaging her kind. Which he was beginning to think was her driving force in her interest of him. "An infective prion is just a mindless protein that has this weird scary super power which can transform previously normal proteins into its fucked up minions." She lifted her head from her wheeled cart, a sparkle in her eyes that kind of made Castle afraid. "So look, those proteins clump together with nothing to do, and in a normal human infected by a prion disease, they wreak havoc, causing cell death. Imagine what they do in a vampire who uses those proteins."
"Yeah, uh-huh," Castle said, nodding and playing along. He mostly didn't follow a word she said.
"When you're transitioned and the VL changes one of the human body's clinically insignificant RBC glycoprotein antigens into a clinically significant one?" She looked at them both, a bit of milkshake dribbling over the lid, apparently expecting them to be profoundly elucidated. "You know, the one that runs in vampire lines and makes your blood less compatible with other vampires? Anyway. You could say that this new RBC glycoprotein antigen is a PrPC that is specifically susceptible to Vampire Prion disease—which we call PrPV, for shits and giggles."
"Riiight," Castle answered. He pointed to the milkshake. "And what's in this one?"
"Same. Since we don't want her getting out of balance, we're going to up your doses of alliicin. Giving the VL algae in your bodies this dump of alliicin so the algae has something to do, fighting it off. A reason to live, so to speak."
"Um, wasn't the fungal side of things already too powerful?" he asked. "Wasn't that her problem?"
"You've been listening! Gold star for you, Mr Castle."
He beamed at Kate to share his gold star pride and she only rolled her eyes, grimacing on the taste of garlic and onion smoothie, no doubt.
"So how is this garlic supposed to help?"
"Garlic and onions have a natural alliicin-creating property which helps clear up fungal infections."
"Yeah but don't we need some of it?" Kate rasped. "You said it's a lichen, which is both algae and fungus. I feel like I just drank an atomic bomb and you've wiped out all my good fungus."
"Look at Ms Beckett, pretending she knows shit."
Kate scowled.
Castle might have giggled but he smothered it quickly.
Dr Harris gave Kate a long stink-eye and then explained. "The allicin in garlic is a thiosulfinate—which is a reactive sulfur species that undergoes a powerful redox reaction with thiol groups. Glutathione—one of those thiols—is needed in plants, fungi, and animals to repair cellular damage. When exposed to allicin, the glutathione is changed and the cells die. Thus allicin/garlic has a potent anti-fungal effect."
"Yes, right, isn't that basically what I just said?" Kate growled. "Ug, this stuff tastes foul."
"I think," Castle said cautiously, almost astonished by how quickly his brain buzzed with information. "I think it's because the VL isn't just a fungus, but a lichen. A cohabitation, so to speak, of both the fungus and the algae. So to jumpstart the algae, you start battling at the fungus."
"Another gold star—"
"Enough," Kate spat. "Castle, your turn to drink that poison down. See if your gold star pride lasts through that."
Dr Harris raised a slim eyebrow but handed over the glass of garlic-and-onion slime.
He dutifully took it, paused at the smell. "Um. So if she's drinking from me, why is that I need this? Because she's the one—"
"Drink, Castle," his wife snarled.
He drank. Gagging all the way.
Harris washed her hands with an alcohol pad. "You're basically right. The algae component produces a protein that acts as an alliinase inhibitor—which proves symbiotically beneficial to the fungal component so that it doesn't die when exposed to alliin (the stable form of the alliicin prior to activation by alliinase, remember?). Now, guess what happens when that algae component's protein stops working or gets, you know, changed somehow—?"
"Oh, is that Kate? Oh shit." He choked on the milkshake but tried not to spew it out all over the doc in his excitement. "You mean you think Royce was diseased?! He had the vampire prion disease?"
Kate jerked her head around to the doc. "Wait, what?"
"Gold star, Mr Castle. A hundred gold stars. I think Kate's had a version of that prion disease all along. Which makes her—both of you—really damn interesting for my research."
"Holy shit."
"That doesn't make sense," Kate growled. "What are you saying—but Castle? Why doesn't he have it too?"
"Because you did something very stupid and drank a whole person, Kate Beckett. You'd been shot, you lost more than half your own blood volume, I'm guessing, because you didn't stop to do first aid on your own three gunshot wounds—"
"Kate," he croaked, gagging on both garlic and that horror. "You didn't even stop your own bleeding?"
"I didn't have time. You were dying."
"You were dying!"
"Hush, children, listen to what I'm saying." Dr Harris put her hands on her hips, glaring at them both now. "Kate replaced half her own blood volume or more with what was fortunately a blank slate. I can't imagine how it couldn't have been anything but O neg, but even so, it wiped out whatever RBCs had those ineffectual proteins." She glared at him, pointed to the milkshake.
Castle obligingly began chugging it down.
Dr Harris gave a prim nod. "And no, they weren't vampire proteins, but some of her VL load remained—in you, Rick Castle. When you healed her that first time, and then the second, those high loads of VL in your saliva met the garlic-thinned donor blood, and you recolonized her system. This time with a new RBC glycoprotein antigen that your system had created when you began transition."
He almost had it; he felt like the understanding of the vampire lichen which was now creating the heat in his blood was right there, so close, and yet overshadowed by his own lack of medical knowledge. But he trusted it.
He tipped back the glass and swallowed the last of the garlic-and-onion shake. When he came up for air, his wife looked devastated.
Kate had buried her head in hands. "Castle saved my life," she rasped. "In so many ways."
He was astonished by the sheen of tears, so thick as they fell that she had to repeatedly swipe at her cheeks.
She took a shaky breath. "And what have I done to him but ruin—"
"Oh, hush," Castle muttered. "As Dr Harris would say. This is the coolest thing ever. I'm down in a vampire's lair having some of the best orgasms of my life, so—"
Before Kate could admonish him, there was a terrible rending noise in the negative pressure room, and the scent of sulfur and rotten eggs filled the already-close air.
"Did you… fart?" Kate croaked.
Castle's ears burned and he gave a nervous chuckle. "What's in this thing?"
Dr Harris was holding her nose as she said, "Powerful redox reaction of a sulphur species. The fact that Kate isn't farting is a bad sign. That's why we're doing this, remember? We need to put her back in balance."
Castle held out his hand to Kate. "Want to fart with me?"
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