Oven

When Jack rounded the corner, there was a too-tight blue button down shirt and flippy blonde head of hair crouched by the oven.

Now, this in itself was cause enough for alarm. Mac knew damn well—or at least, he should've known—that the house rules stated he was not allowed within a five-foot perimeter of the kitchen while any appliances at all were active. Exceptions could be made for warming up takeout, but after the Christmas Eve incident that left the house down one microwave, up several scorch marks, and in need of a new window, even that required some level of supervision, as per the Bozer's orders.

And yet, there he was—the wunderkind himself—crouched on the kitchen tile and running some sort of smacked-together doodad made of duct tape, magnets, and a gutted calculator over every inch of a very hot oven.

"Hey, hey hey hey!" Jack trotted into the kitchen as fast as he could, grabbing an oven mitt off the counter as he went to swat at Mac like shooing off a stray cat. "How many times do we have to tell you you're not allowed in the kitchen?"

"I'm not gonna try to make something." If Mac sounded defensive, the tone petered off slightly as he got distracted again. "I'm just...testing a hypothesis."

Jack tugged open a kitchen drawer, tossed the oven mitt into it, and continued to pull various utensils out of the dry rack to put them away too. "Well, can you take the hypothalamus somewhere else?" he asked, half over his shoulder. "We only got half an hour left to wait, and dinner's gotta cook, man."

"Hypo—" Mac paused, frowned, and looked over his shoulder, leaning on his raised knee. He almost sounded impressed. "How did you get 'hypothalamus'?"

Jack shrugged. He tried not to look too proud of himself. "I dunno, you say it all the time."

Mac shook his head, which made his bangs flip into his eyes again, and turned away. "It's 'hypothesis', and that's just it." He narrowed his eyes, peering through the cloudy oven window. "It's not cooking fast enough."

Jack leaned back against the counter with a scoff and tossed a utensil in the air, catching it in the same hand. "Look, if you're gonna pull out some bullshit math like 'what's done in three hours at four-fifty can be done in three minutes at four-thousand-fifty', I'm gonna crack your noggin open with this turkey baster, brother."

"No, no, that's stupid," Mac snapped back, "it doesn't make any sense. You're not taking into account convection and how heat permeates matter." He ran his hand back through his hair in frustration. "That's not what I'm talking about."

Then—bracing himself for exactly what would happen the moment the words came out of his mouth—Jack asked, "Then what are you on about, hoss?"

Sure enough, Mac stood up with both fingers pointed at the sky, and made eye contact with Jack for one split second before he was immediately consumed in Explain-A-Ma-Tron Mode and was blind to anything else but the inside of his own brain.

"Every time you or Bozer bake something, the kitchen heats up." He turned and leaned over the stove-top, stretching his skinny arms to try to reach his duct tape doohickey behind the oven. "Which tells me," he said with a grunt of effort, "that the oven isn't insulated properly, and it's letting heat escape somewhere."

Jack shrugged and pulled his lips down in a 'well, that's true' face that Mac didn't see.

"It has to work harder to get up to temperature and stay there," Mac went on, crouching by the oven door again, "which means there's wasted energy, which means it's inefficient."

Jack shrugged noncommittally. "Sounds like you and the Boze-man gotta get a new oven."

Mac stood up again, staring dead-on at nothing, and there was such a determined steeliness in his eyes that it would've made anyone with half a brain step back—anyone, that is, who didn't know him as well as Jack did.

"Not if I can fix this one," he said, and stalked past him.

Damn. He was so focused on this that he didn't even bother to nitpick Jack's grammar.

Jack just shook his head and hollered over the clatter of the kitchen drawers that Mac was already rummaging through. "Hey, there's a time to be thinking about that, Einstein, and it's not when I'm making a roast!"

Mac fished something out, tucked it under his arm, and then his skinny little legs had him up and down the hall towards the garage in a flash.

"Mac!" yelled Jack.

"I need more tin foil!" came the distant yell back.

Jack rolled his eyes heavily and turned away.

If there was no stopping this bat-crazy kid, Priority One was making sure the roast survived.

A/N: A new friend got me into a new (actually old but never mind) show, and something popped into my head while I was making dinner today, and my hand slipped. C'est la vie.