Nineteen-year-old Phineas Flynn was on his summer break and sitting in a car with his girlfriend Isabella Garcia-Shapiro. The two had started dating just before starting their first semester in college, after discovering that Isabella had had a crush on him since they were little. Their relationship had had its ups and downs, but they were deeply in love and felt they would be together for as long as they lived.
They were on the way to the airport to pick up Phineas' step-brother, Ferb who was studying abroad in England. They were also picking up Ferb's girlfriend Vanessa, an older woman who had gone with Ferb. She had already graduated college with a double-major in music and education and had big dreams of being a famous musician. These had not yet come to pass. She had been working on cruise ships as a singer, but became a music teacher in an English high school after she had moved there with Ferb. She didn't mind, as she knew dreams took time and if she didn't fight for it she'd regret it.
Phineas and Isabella pulled up to Danville's international airport. Phineas was eager to see his brother again, whom he hadn't seen since last Christmas.
Isabella pulled her car into the parking lot.
"Thanks for driving me to get Ferb," stated Phineas. "And don't worry I'll pay for the parking."
Phineas still didn't have his own car, so had agreed to pay for any additional expenses they might incur while on the way to the airport. He was just glad Isabella had agreed to drive him.
"Don't worry about it, I'm just glad the gang's getting back together this summer. It feels like it's been an eternity since we last saw everyone," stated Isabella, locking her car.
"Well the gang and then some," joked Phineas.
Vanessa hadn't been a part of Phineas and Ferb's gang when they were younger. She'd had her own group of friends and when she did hang out with Phineas and Ferb it was usually through their older sister Candace.
"Hey, I think Vanessa's become a member of the gang in recent years," stated Isabella.
"I guess, but I hope it's not too weird for her to hang out with a group of college students," said Phineas.
"She's dating a college student," stated Isabella.
"True. Well, I guess there's nothing to worry about. There almost never is," mused Phineas.
Phineas' optimism was one of the many things Isabella loved about him.
They entered the airport and quickly spotted Phineas' green haired brother and his brunette girlfriend, waiting for their bags.
"Ferb, Nessa!" called Phineas.
They turned and smiled. It was great to see them again.
"How's school in England been?" asked Phineas.
"Cool! I'm taking the most advanced classes, but even they don't keep me busy for too long," answered Ferb.
"I see Nessa's still getting you to open up a bit more!" observed Phineas.
Ferb had always been a man of few words, often going a whole day without uttering a single word. Ever since he'd started dating Vanessa though he appeared to be talking a little more everyday.
"Well, even though she likes the strong silent type, she says that communication is crucial if we're going to have a relationship!" explained Ferb.
Phineas laughed.
"So Vanessa how's the teaching going?" asked Isabella.
Vanessa crossed her arms.
"Honestly, I'm just glad I don't have to grade any papers for the next few months," she answered. "I was forced to hand out summer homework as part of the curriculum and I honestly dread to see what my students hand in."
"Hey, I'm studying to be a teacher too, it can't be that bad can it?" cried Isabella.
"You won't have a classroom filled with students who believe the class will be an easy pass. Most of my students refuse to pay attention and they wonder why I hand out so many failing grades," sighed Vanessa.
"Well, how are your other musical plans going?" asked Isabella.
"I sing at a lot of open mike nights and karaoke bars. I've even been offered auditions for a few up-and-coming bands, but I feel I should wait for Ferb to finish college before I pursue some of my bigger dreams," said Vanessa.
"Afraid other girls will flirt with Ferb while you're away?" teased Isabella.
"No, I'm more worried that Ferb will never leave his dorm if I go away. Even he thinks he'd spend all his time shut in his room inventing if we weren't dating. Believe me, other girls flirting with him is the least of my worries," answered Vanessa.
"You guys spend a lot of time together?" asked Isabella.
"We certainly try," sighed Vanessa. "I'm usually busy with lesson plans, grading papers and writing music, but thankfully Ferb finishes all his college work very quickly, so he's almost always able to go out when I ask. He's also been a big help with some of my music writing."
"Well sounds like things are going well between you two," stated Isabella.
"As well as they can be I guess," agreed Vanessa. "What about you and Phineas? Things going well between the two of you?"
"Well, I'm just thankful we go to the same college, meaning we see each other almost every day. Plus, Phineas also completes his work very quickly so whenever I wanna go out he's almost always available."
Vanessa laughed.
"Is it just me or are we dating the smartest guys on this planet?"
"I think we are Vanessa, I think we are," laughed Isabella.
Vanessa and Ferb spotted their bags and soon were loaded in Isabella's car ready to drive back to Phineas and Ferb's childhood home. What they didn't know was that there was a surprise barbeque for Ferb to welcome him home from college.
The drive was filled with fun stories of college and laughter from everyone. Life was good for Phineas and Ferb. They were both dating the girls of their dreams and it seemed impossible for anything to go wrong. Little did they know that horror would soon befall the entire planet. Horror they could hopefully prevent.
Meanwhile, at the Danville Natural History Museum a large purple portal appeared around the 'incomplete' time machine exhibit. The machine was replaced with what looked like an older more rustic version of the current machine. On board were two young, uniformed soldiers who had their eyes tightly closed.
"Did we make it?" asked the male soldier.
"Well, we're still alive," said the female soldier.
Despite this, both were hesitant to open their eyes just in case their efforts had failed. The female soldier decided to risk it and slowly opened her eyes. The museum was different to how they remembered. It was cleaner, appeared to be in use, it had been night-time when they'd climbed aboard, and the most significant change was that there were other people looking at the exhibits.
"Sean, open your eyes we made it," she exclaimed.
Sean opened his eyes and saw the same.
"Rose, have I ever told you you're brilliant!" he stated.
"Yes, but you don't say it enough," she laughed.
Sean was about to climb out but Rose stopped him.
"Wait, maybe we should put our weapons away," suggested Rose. "The people here won't understand where we're from or what we've seen."
"Good idea," said Sean.
He pressed a button on his plasma rifle and it shrunk to a size for him to carry it in his pocket. This functionality had been devised so the resistance could carry multiple weapons at once. Rose also shrunk her weapon as they climbed out of the time machine.
While they knew time was of the essence, they couldn't help but admire how different the world looked to the one they knew. Even though the museum wasn't particularly packed, it had been a long time since Sean and Rose had seen so many people gathered in one place. Outside was even more of a spectacle. The Danville they knew had been an abandoned city with rundown buildings and empty streets. They couldn't believe they were in the same city. The Danville they now saw had well maintained buildings and there were people everywhere casually going about their day, completely unaware of the horror that would soon befall them.
"Well, now what do we do?" asked Sean.
"Isn't it obvious, we get to Phineas and Ferb's house and convince them to help us stop the war before it begins," answered Rose.
"And how to you propose we do that? By walking?" asked Sean. "It could take us days to get to their house."
"Well, I was told about this thing called public transport. It was apparently huge in large cities like this," stated Rose. "Only problem is, you have to pay for it, and we don't have any money."
"Actually, I might have a solution," claimed Sean. He reached into his jacket and pulled out a plastic bag with a large wad of cash.
"Where did you get that?" asked Rose.
"You know that abandoned bank we were hiding in two weeks ago?" asked Sean.
"Yes?" answered Rose.
"Well, I knew needing money might be an issue while we were here, so I broke into the vault while you were sleeping," stated Sean.
"Seriously?" asked Rose raising an eyebrow.
"What? It's not like anyone from our time needed the money. Besides, it was probably better to get the money this way then to hack into and steal money from an ATM in the past," reasoned Sean.
"I guess, but what about the dates on the bills?" asked Rose.
"A war that kills off half of humanity will be starting any day now, I don't think we need to worry about when this money was printed. I have a strong feeling it would've been printed before the current date!" explained Sean.
"Whatever," said Rose rolling her eyes. "Let's just get to Phineas and Ferb's house. How do you want to get there, by bus or taxi?"
"I think we'll attract to much attention if we take the bus, let's take a taxi," suggested Sean.
"Sounds good," Rose agreed.
After hailing a taxi, they realised they didn't know Phineas and Ferb's address. Because of this they let the first taxi go. They didn't know how they were going to find Phineas and Ferb's house, when Rose remembered something else she'd been told about the time before the war. She'd been told there were pay phones spread throughout the city and they often had what was called a phone book, which showed a person's phone number and address. It took them awhile, but they eventually found one and sure enough it had a phonebook inside. Thankfully, Sean and Rose knew Phineas and Ferb's surnames. They also knew that their parents were called Linda Flynn and Lawrence Fletcher, which allowed them to easily find their names among the F section. Rose tore out the page from the phone book so they didn't forget the address.
They hailed another taxi and asked it to take them to Phineas and Ferb's address. They just hoped the famous duo would be home when they got there. They also hoped that the brothers would be up for the challenge. Sean and Rose had a bad feeling that the Phineas and Ferb they would meet in this timeline would be vastly different to the Phineas and Ferb they'd known from the war. Regardless, Sean and Rose still knew they were the best chance they had of preventing the war.