Buffy hides a smile behind her hand, trying not to laugh at the flabbergasted look on Tony's face.
"Really," she says brightly, once she's sure she's got her own expression under control. "This is what breaks your brain? After snarking your way through the 'not just your PA' talk, and Faith going behind my back to give you the 'World is Older Than You Know' speech, and fighting that tentacula thingy in Cleveland, you go Blue Screen of Death on me over a little dusting?"
He blinks, and the wide eyes and stunned expression give way to a melodramatically offended look. "A little dusting?" he objects, gesturing at the pile of grayish particles on the sidewalk. "You just folded, spindled, and mutilated the laws of physics right in front of me!"
"Yeah, and...?" She can't quite keep the laughter in this time. "I know you've been having JARVIS keep track of what I can do since I stopped trying to keep a lid on it all the time. What, do you seriously think I get my powers from little nano-thingies in my muscles or a serum like Steve? Or that Big, Blue and Slimy last week was actually using electrical force shields, just hiding the tech where you couldn't see it? You've worked with mutants. And you remember Loki, right? Not to mention your teammate, the God of Thunder?"
"I know you might have missed this part, seeing as how Fury didn't have you in his pocket at the time, but Thor and Family aren't actually gods," he says, spine straightening as he flails for mental purchase. Buffy gets that, but she hopes he gets over it quick; she's never enjoyed verbal slapfights. "They're aliens," he emphasizes. "And that means...."
"Clutch Clarke's Third Law to your outraged bosom all you like," she raises an eyebrow at him, "and yes, I actually do know what that means; I've known a nerd or two in my day. Did you think Faith was exaggerating? Trust me, she wasn't. Vampires are demons. Dee Eee Emm Ohh Enn Ess. Do you seriously think this," she waves Mr. Pointy in his face, "is actually strong enough to punch through ribs? No; what matters is that it's carved out of wood. Its sole function is to disrupt the magic, Emm Ayy Gee Eye Cee, that keeps an undead body undead instead of rotting in the ground."
"But why?" he objects, snatching the stake out of her hand and staring at it in frustrated bafflement. "Even the wildest mutations have rules and restrictions. Magic doesn't! Case in point: what makes wood so special? Do you treat it with anything? How does it catalyze a complete disintegration, if it's just one bunch of dead organic cells piercing another? Is there some kind of miniaturized accelerated entropy field involved? But if so, why did your stake survive, and not his clothes? And speaking of JARVIS' observations, how can you possibly expend the kind of energy you do all the time without lighting up his infrared like a bonfire?"
She cuts him off before he can drag the conversation too far off track. "Just because magic's not rational doesn't mean it doesn't have its own logic; you just don't know what it is," she says, ticking the points off on her fingers. "I don't remember why wood's so important, except that it's a symbol of something; magic's usually all tied up in symbols and meaning, you'd have to ask my friend Willow for the deets. No; it's just a piece of dead tree. If you can figure out a way to put a sensor on a vampire while it's going poof without losing the sensor too, knock yourself out. No idea; I just work here. And I'd guess it's something to do with the Slayer healing factor, but your guess is as good as mine on that one, too."
He stares at her in horror as she grabs the stake back out of his hand and tucks it into her waistband. "You just work here? My God, woman, if I was that incurious, I'd be dead now," he says, tapping a thumb against the glowing triangle shining through his grease-stained tee shirt.
"Been there, done that," she rolls her eyes. "But that's why you're you and I'm me. And speaking of your little nightlight, how many people would call that magic?"
"It's not the same thing at all!" he says. "There are natural laws...."
"Like I said, talk to Wills," she smirks, then crouches and vaults straight over him, kicking off his shoulder as he stumbles backward to gain extra height. When she comes down again, she has Mr. Pointy in her hand once more, and the vamp sneaking up on her boss gapes like a fish as she strikes down on him like a bolt of lightning. He crumbles into dust, leaving an earthy smell behind; it had been pretty plain he was brand new, which is why she'd felt free to indulge in a little show.
"You make great bait, by the way," she adds, nonchalantly. "It usually takes me a lot longer to track down a bloodsucker, these days; I think they're getting suspicious of the blonde act."
Tony's spluttering, brushing at the shoe print on his shirt, but calculations are visibly ticking over behind his brown-eyed gaze now that the shock is wearing off, and she'll bet anything he'll put JARVIS on a new project as soon as he gets back to the Tower. "And why am I the one playing bait, again? Isn't your boyfriend a little more familiar with low-tech weaponry?"
"Because you asked," she reminds him, tartly. "And because I told Clint he can't play until he switches out some of his neat-o composite shafts for old-fashioned wooden arrows. Not that he's actually my boyfriend. If you call him that where he can hear and scare him off..." She shakes a finger at him, trying to come up with a sufficiently evil threat; working for a superhero with something like twice her IQ means she has to be especially creative. "I'll reschedule all the next quarter's quality control inspections to the same week-- and tell Pepper you're having a time out."
He shudders theatrically. "Now that is evil. But if you put it off too long, I'll tell Pepper, and you know what she'll do. She likes Barton; if I start hinting that you need a little help matchmaking...."
Buffy wrinkles her nose, laughing. "All right, all right, truce. C'mon, we've still got a ways to go before we run into the territory of that guy with the horns on his costume. And then I'm sending you home to Pepper; you've got that meeting with Faith and the Wolfram and Hart guys she was supposed to be briefing you on first thing in the morning."
He groans at the reminder, but seems oddly less foot-draggy than she'd have expected; she'll have to grill her sister Slayer soon about just what she's said to him. "Remind me to ask Barton about the arrows, later," he adds. "I'll bet he does his own fletching, and I want to see his process."
"Meddle with it, you mean," she replies, but makes the mental note.
Now all she has to do is talk Tony into hiring a non-Slayer ISWC alumna to back her up. She has a feeling Fury will be calling on their agreement a little more often now that vamp traffic is picking back up and she's broken the alternate identity thing to the other Avengers.
Buffy doesn't mind, though. What other job would let her have her cake and eat it, too?
She smiles to herself as she spots another vampire, and drops back behind her boss to await the perfect moment to pounce.