Chapter 1: Irrelevant
"What Do We Want? TIME TRAVEL!
When Do We Want It? IT'S IRRELEVANT!"
"You're not impressed." The man calling himself 'the Doctor' said with an absentminded frown as Phineas and his brother split up to explore the giant alien ship. "You're really not that impressed! Rory, look, they're not that impressed."
The mousy brown-haired man looked up and shrugged at the Doctor. Rory, Phineas thought his name was. Like a lion. "I wasn't either, Doctor." He said with bland air.
"Oh, who asked you." The Doctor waved dismissing hand at him. "Pond!"
"Duly impressed." Amy, the red-headed woman leaning against Rory said with a lazy mock salute. "Sir."
"Right. See?" The Doctor pointed to his companions. "Impressed!"
"Well, it is sort of impressive." Phineas concurred. It looked like a blue 1960s British Police Box on the outside, but the inside seemed to be some sort of giant mammoth labyrinthine complex inside. "But Ferb's a master of space management. He's not quite Olympic-sized Swimming Pool and-" He glanced down the hall "-full sized Bowling Alley level just yet, but we're working on it."
Ferb glanced up from the clipboard where he was writing what parts they were going to need and flashed them a thumbs up.
"Right." Amy said with a snort. "So he's what? Minus the Bowling Alley part?"
Phineas looked over at his brother, who waggled a hand. "Pretty close." Phineas agreed, crouching down to look under the main console that took up the majority of the room, noticing the bundles of unbound wires hanging loose. "Looks like you guys really are in some need of repairs."
"Well, that's why we're here." The Doctor nodded. "Not that I can't do it myself, of course, but Garbog said that you did a bang-up job on both his and Meap's ships."
"The question is-" Rory raised a finger. "-Can you do it?"
Ferb hopped out of the overhead duct work and handed Phineas the clipboard. Phineas quickly flipping through it. "Mostly, yeah. There are some things we don't have or can't build from scratch with the parts we have on hand, but we can at least clean her up a bit and do a tune-up."
Ferb nodded, patting the railing next to him fondly. The ship had a good feel to it, which would make repairs that much easier.
"And how long is that gunna take?" Amy asked. "Are we talkin' 'bout being here fer a week or so?"
"Eh... Not quite that long." Phineas glanced at Ferb, who thought it over for a moment before nodding. "-The afternoon should do it. Or a couple of minutes if everyone pitches in, we get a good song and a musical montage going." Phineas concluded.
"Right. Montage. Montage it is." The Doctor said with a manic grin and a clap, rubbing his hands together. "Now, who's got a good song?"
Chapter 2: Meanwhile....
And on the other side of town, Doofenshmirtz was busy building his latest creation...
He doesn't know what it does either.