“‘O holy UV-B light source, purify me of sin’?” Greta said, looking skeptical. “I don’t think they had those back when this sect got started.”
“’S like that Ursula Andress movie.” He finished twirling the spaghetti, conveyed it to his mouth, and used the now-denuded fork to gesture. “With Stacy Keach. Something Something of the Cannibal God. Ursula and supporting cast were exploring a primitive volcanic island staffed by cannibals, like you do, and found the locals worshipping a dead guy with a Geiger counter stuck in his chest cause they thought the clicking was the sound of his dead heart still beating. You know. Object taking on talismanic significance. Cargo-cult stuff.”
“But a lightbulb?” Varney said, interest in the subject apparently overtaking mild revulsion at Cranswell’s table manners. “And these aren’t superstitious cannibal tribes. They’re … well … as Dr. Helsing says, we don’t know who they are. Just that they can spell quite long words in garlic juice on people’s walls.”
“Religious mania is capable of prompting some pretty messed-up behavior,” Cranswell pointed out. “People do all kinds of stuff because God tells them to. Why shouldn’t God be a lightbulb? He’s already been a whirlwind and a burning bush, just to select two examples completely at random.”
“Wait,” said Ruthven, holding up a hand, looking into the middle distance with the preoccupied expression of someone tracking down an elusive thread of memory. “Wait. Underground, right. The Underground. There’s all sorts of electrical switchgear and so on to run the systems down there.”
“I think the transport authority would notice a bunch of crazy monk guys genuflecting to their light fixtures,” Cranswell said. “Like, even in London that’s weird.”
“Shut up, I’m thinking.” Ruthven’s hand, still lifted, tapped gently at the air as if to jar loose whatever he was trying to remember. “Trains and electrical switchgear … electrical switchgear … I’ve nearly got it.”
“I had an electric train when I was a kid. The transformer that came with it was this little dinky piece of shit that was always overheati—”
“That’s it!” Ruthven thumped the table, making them all jump. “Sorry. That’s what reminded me, when you said transformer. I know what the blue light is. I mean, I think it has to be.” He beamed at them in satisfaction. “Nothing else fits all the requirements, the blue light and the humming-hissing sound and the mercury vapor and the ultraviolet radiation and the, well, the talismanic significance, as you so precisely put it.”
“What fits the requirements?” Greta demanded.
“Oh, sorry. It’s not a lamp at all, it’s a mercury arc rectifier. Electric railways had them, that’s what made me think of it. They were pretty much the standard up until, oh, the sixties or seventies, when thyristors took over. Pity, though of course solid state was less dangerous and took up less space. Very few of them are still actually working these days; they’re museum pieces, quite apart from the toxicity thing.”
“I don’t understand what you’re talking about,” said Varney, enunciating with irritated clarity, and Greta and Cranswell shot him identical grateful looks.
“Used to have them in carbon arc film projector setups, too; you had to have DC to run the arcs,” Ruthven went on, and then apparently finally realized he’d lost his audience. “Look, I’ll show you.” He took out his phone and did a quick YouTube search. “Here’s the one from the Manx Electric Railway that was still in place up until a few years ago.”
All three of them crowded in to stare at the little screen; it was playing a video clip of something that was at once wonderful and terrible and profoundly hypnotic.
Cranswell was looking over Ruthven’s shoulder. “It is a lightbulb. With legs.”
It did, in fact, resemble one: a giant blue-glowing glass bulb, six angled legs jutting out from its walls just above the base, looking vaguely tentacular. The flickering unsteady glow was brightest in the hollow glass tubes of the legs, each of which bent ninety degrees before giving itself up to a graphite fitting and a coiled, curled wire. In the base of the bulb lay a miniature lake of mercury, on the surface of which danced a glaring brilliant blue-white spark. Far too bright to look at for long, the moving spark seemed to describe strange patterns on the liquid metal: sigils that might make sense if you could only watch long enough to follow them, that—despite the danger—made you want to try.
When it was over, nobody protested when Ruthven played the video again, turning up the volume so the humming of the thing was clearly audible over the tour guide’s chatter.
“Good heavens,” said Varney quietly. “I don’t think I can blame them for thinking that thing could have supernatural powers. What are the legs for?”
“Anodes,” Ruthven said. “It turns AC into DC. For reasons I won’t go into, the mercury vapor only conducts current in one direction. It’s a valve that only lets current pass one way.”
“I’ll take your word for it,” said Greta. “If that’s basically what amounts to a great big unshielded UV lamp, it could probably do the kind of damage I saw. If he’d been exposed to it for … well, quite a while.”
Ruthven glanced at her, eyebrows raised. She shrugged, not really wanting to examine the thought too closely. “It would have to be hours. Several hours.”
“Like I said,” Cranswell put in, “doing vigil or penance or what-have-you.”
Purifying them, Greta thought, and winced. “UV sterilizes,” she said. “It is literally germicidal; it’s actually one of the ways you sterilize things in a lab. Ugh, it does fit, doesn’t it? Burning away the dross.”
“How does this thing confer on them the … the supernatural powers we have witnessed?” Varney asked impatiently. “Their eyes, how does it make them able to see through objects when their eyes are obviously blinded?”
Cranswell nodded. “And how does it make ’em glow blue while it’s at it?”
“That is, I think, where the supernatural aspect comes in.”
With almost comically coordinated timing, they looked up from Ruthven’s phone to see Fastitocalon leaning in the doorway, looking haggard but focused. “Because, make no mistake, they are supernatural,” he continued. “It takes one to know one.”
“What are you doing up?” Greta demanded.
“Providing the demonic viewpoint. No,” he added, lifting a hand, “please don’t start with the lecturing, I’ve had rather more than enough of that for one day, and I’m quite capable of rational discourse.”
Greta looked mutinous, but just sighed and got up, gathering the plates. “I’ll put on a kettle,” she said. “If we’re going to have a council of war we might as well have a nice cup of tea while we’re doing it.”