Rose is barely in world number seventeen for a minute before she hits the button and is back by Mickey's side.
"That didn't take long," he mutters, totally absorbed by his computers.
"Yeah, well, the sky was green," Rose announces, inspecting the Dimension Cannon carefully. "Pretty obviously not the right one." Something feels off, so she hands the cannon over to Dr. Sato, who's responsible for most of the cannon's hardware - Mickey did the software, and Rose handles the testing, though they all know enough about each other's job to get by should rogue Cybermen eliminate one of them. "Think it needs a new battery." Dr. Sato cradles the cannon gently, fussing over it like an infant.
"How d'you know the sky wasn't green at that very moment 'cause some alien had made it so?" Mickey wonders thoughtfully, entering the new data. "Maybe the doc was right around the corner, fixing the green problem."
"What your coordinates said was London was a desert," Rose snaps, "so unless you're saying something's wrong with your - "
"Hey, now!" Mickey throws up his hands in an effort to deter her. "I'm not being serious about it Rose, just passing time."
She sighs. "It just... feels wrong. Even when it's not something obvious, I can tell. You know?"
Having finally given in and traded out the power core like Rose suggested, Dr. Sato hands the cannon back. "It's using up more energy than I expected," she says. "If we don't find your 'proper universe' in the next few jumps, I'm going to request access to some higher level alien energy sources, even though it's not in our budget."
"I keep telling you, that thing you two put together, on the stars going out, on what the Dimension Cannon working means, it's good, but it hasn't been read by anybody with real power," Mickey says absently, attention back on his coordinates program. He changes a few variables, adding, "You have to go up to Pete yourself and explain it to him, dumb down the science talk, and then we'll have ourselves a budget. And a few interns too."
"Because what you really need is a teenager to boss around and get you coffee," Rose says, rolling her eyes. She straps the cannon back on, double-checks a few features, and nods. "Thanks, Dr. Sato, everything looks fine. But maybe put in that request now anyway - and ask for something rechargeable? Something that runs on solar or Void stuff would be great." She stretches, turns off the safety on her gun, then nods to Mickey. "Ready when you are!"
"Alright," he crows, transmitting the next set of space-time coordinates to the cannon. "Let's try - "
Rose slams on the button before he can finish his sentence. For a minute she's nowhere at all - not that she's aware of it. She thanks god every time she recalls the Daleks' Void ship, that the Dimension Cannon isn't like that, that she doesn't spend an eternity in that nothingness... or that if she does, she can't feel it. However long it takes her to get through, it's only a matter of seconds to find her bearings and take a look around the latest parallel universe.
World number eighteen seems alright at first. The sky's blue above the skyscrapers, the grass between pavement and house is almost green, and the air tastes right - a little light on the petrol, maybe, but there might've been an oil crisis or something. She notices something in the air after a minute or two - not a wrong taste, though now that she thinks of it, there is something else off about that - a little silver ball, covered in odd markings.
It floats down to hover in front of her with a little buzz, and it suddenly strikes Rose how very quiet it is here. And not just quiet for London - she doesn't think she's heard a car drive by, or a door close, or anything at all, really, in the five minutes she's been here.
"Hello," the silver ball says in a tinny, childlike voice. "We haven't seen you before."
Rose knows better than to trust a voice just because it sounds nice and innocent. She puts her hands behind her back, setting the return coordinates on the cannon by touch. "Yeah," she says cheerfully, hopefully sounding innocent too, "I'm kinda new in town? D'you where I might find... the Doctor?" Odd as this ball-thing is, Rose can't deny that this universe feels as close to home as she's gotten. Maybe it's like Mickey suggested - maybe this is an invasion in progress the Doctor is about to defeat.
"The doctor? Do you need a physician?"
"No, no! Just the Doctor."
"The... Doctor?" The change in pronunciation is small, but it gets Rose's hopes up. Maybe, just maybe... the ball hums mechanically for a moment, processing something, and then it shoots out a whole bunch of wicked-looking spikes and blades. It flies at her, blades spinning, saying, "You don't look like - "
Acting on instinct, Rose shoots the thing before it can finish speaking; it starts sparking and shuddering maybe two feet from her face, and after she turns to run it explodes with enough force that she hits the ground hard, stunned. As she's blinking spots out of her eyes she hears that buzzing sound again, about ten times as strong. Her gun's going to take a few minutes to recharge, and she doubts she can fool this group for as long as the first. Hoping the coordinates hadn't gotten shifted around while she was blowing up that thing, she slams on the button.
The buzzing stops.
She opens one eye cautiously. Mickey's bent over in front of her, a worried look on his face.
"You've got a tear in your pants and - is that blood on your gun?"
It turns out she skinned her palms raw on the pavement when she fell. She winces through the application of disinfectant and bandages, and again through the looks Mickey gives her while transcribing her oral report. Dr. Sato, when she arrives with a new battery to experiment with (and new technical support staff by the name of Adeola, who gives Mickey a look that says he will be bossing no one around), looks equally concerned.
"And this universe was the best one yet?"
"Not the best," Roses insists, "just the one most like home."
Adeola tuts. "If that's what home is like..."
It frustrates Rose, but she doesn't have the words to make them understand. They've never lived in a universe that wasn't the right one - and Mickey, who current does, is more worried about Rose right now than getting her home. With all three of them insisting that she take off for the day, Rose doesn't stand a chance.
Not that she doesn't still make an attempt.
"But - "
"With Mickey's help, I should be able to turn that Dimension Cannon into a Doctor detector, and that'll help us pin-point things," Adeola says. "But it will take time. Go home."
"I can still - "
"This latest energy source can be powered by solar, temporal, or electrical back-up power, but I'm going to have to take the cannon apart to install it," Dr. Sato says firmly. "Please, go home."
"Is it really - "
"Go home!" Mickey finally shouts. "I'm gonna fine-tune the coordinates program some more, but in an hour I'm stopping by the mansion, and if I don't find you playing hide and seek with Tony I'm telling your mother on you."
"Are you joking?" He doesn't look like he's joking. "Mickey, that's low."
"Rose, sweetheart, it's not just your hands. You look exhausted."
Adeola hands her a mirror, and... well. It's possible Rose has had better days.
"This thing travels in time too, remember? We don't have to rush that much."
"...fine, I'll head home," Rose concedes, which gets a wide grin from Mickey and relieved smiles from the others. "But if you think I won't be back again first thing tomorrow morning - "
"Go!" Mickey says, waving her off. "Worry about tomorrow tomorrow! We'll have you back with the Doctor, worrying about yesterday three days from now again in no time."
Rose leaves, smiling at the thought. She's gonna hold Mickey to that promise.