Next Generation and other OC's created by me.
It took a while for the Flynn-Fletcher family to recover from Meap's statement.
"Meap are you insane? We're not sending our kids back in time to deal with Mitch it's too dangerous," said Isabella.
"It's the only way. And remember all of you would've done the same," said Meap.
"Meap when we were kids, we never stopped to think about how dangerous a mission of this capacity would be. We also never stopped to think about how much this would worry our parents," said Phineas. "As parents ourselves there's no way we can deliberately put our kids in danger like that."
"But it's the best way to ensure the timeline remains secure," said Meap. "If you run into your past selves, they might recognise you. I think it's less likely they'll recognise their future children."
"And what if they do. If our younger selves recognise Sean, Rose, Terri and Kenny as their future kids it could alter reality as we know it," said Phineas.
"It won't," said Meap.
"How do you know?" asked Vanessa.
"You're just gonna have to trust me," said Meap.
The parents still didn't like this as there was an extremely high chance that things could go wrong and none of them wanted to think about what might happen if it did. Being the de-facto leader of the group Sean decided to speak up.
"Dad, I'll go. If Meap thinks this is the best course of action I say we go for it. I know it's dangerous, but I'm happy to risk my life to save the space time continuum."
"So am I," said Rose.
"Me to," said Terri.
Kenny gave a thumbs up.
On the one hand Phineas was proud of his son's leadership and bravery, but on the other he still didn't want him or Terri undertaking this mission.
"No," said Phineas.
"But Dad…"
"Sean, while I commend your bravery and have no doubts that you would succeed, I don't want to risk losing you or Terri," said Phineas who started tearing up. "I don't know what I'd do if I did."
Isabella hugged Phineas to comfort him. Sean and Rose could see why their parents were so hesitant to send them back in time. They weren't afraid that they might fail, they were afraid they wouldn't return. Sean and Rose clearly saw that despite the questionable parenting decisions made by Phineas and Ferb, they truly did care for them more than anything else.
Despite the continued objections to send the children back in time, Meap insisted that it had to be them. Meap didn't explain why but insisted that they had to trust him. Ferb however had a feeling Meap knew more than he was letting on. There had to be a reason why Meap insisted the children be the ones to go back and stop Mitch. Ferb had a pretty good idea what that reason was.
"Everyone stop," ordered Ferb. "Phineas, Isabella, Vanessa I need to speak to you privately. Kids, don't move until we get back."
Ferb took the parents upstairs, leaving the kids behind with Meap. While they were away the kids asked Meap about the adventures he had had with their parents when they were children. They also asked him about other adventures and what it was like being an intergalactic security agent. Half an hour later the parents returned.
"Kids get ready, you're going to the past," said Phienas.
All the kids were surprised by this. After everything that happened, they felt their parents would never let them travel through time to stop Mitch. When they asked their parents why they changed their minds they simply said, 'We've trusted Meap before, so we see no reason to doubt him'. Rose thought this was a little suspicious and like her father believed that Meap was keeping something from them. She didn't know what, but she was determined to find out.
In less than an hour the kids were ready to set off to the past. They brought some backpacks containing tools and packed lunches prepared by Isabella and Vanessa. Phineas and Ferb instructed them to seek out their childhood counterparts, as they would need all the help they could get to stop Mitch. Younger Phineas and Ferb would also be able to contact the Meap of the past more easily who's help would be crucial in stopping Mitch. They were now standing outside listening to Sean who had come up with a plan.
"Ok, Mitch went back to this point in time," said Sean pointing at the date on the machine. He then looked at Phineas and Ferb. "So, I'm gonna program it to go back one day prior, giving us time to not only locate you guys, but to also convince you to help us. Finding you will be the easy part because Granma Flynn and Grandpa Fletcher still live at your childhood home. The difficult bit will be figuring out a way to get your childhood counterparts to help us."
Phineas and Ferb looked at each other.
"Honestly convincing us to help you will probably be super easy," said Phineas.
"You're kidding right?" asked Rose. "It took major convincing for you guys to allow us to even undertake this mission."
"We were different people back then. We were the most carefree children you'd ever meet," said Phineas.
"What you gotta understand is that being a parent changes you. It makes you less willing to take risks. Especially with those you care about," said Ferb.
"But we can't worry about that right now. Stopping Mitch is more important," said Phineas.
"Agreed," said Ferb.
Sean programmed the machine to arrive one day ahead of Mitch. He activated the machine and the same bright green portal appeared before them. The parents hugged their children goodbye and wished them good luck. They also reminded the children to only reveal who they actually were if it was absolutely necessary. The parents had a feeling that if their younger selves knew who they were going to marry ahead of time it could greatly damage the space time continuum. Vanessa thought it would be especially shocking if her younger self discovered she married someone six years younger. Phineas also believed he'd have a mental breakdown if he discovered Isabella had had a long-standing crush on him and he never noticed. The four children agreed. They were about to set off, but Vanessa had one more thing she needed to ask.
"Wait, why do you need to arrive a day earlier to locate your fathers? Couldn't you just program it to send it to your grandparents?" asked Vanessa.
"It only travels through time, not space," said Kenny.
"Yeah, that's usually a drawback," said Phineas.
The kids said one last goodbye and stepped into the portal sending them twenty-five years into the past.
Phineas then realised something.
"Wait if this thing only travels through time, then they'll end up in this area twenty-five years in the past right?" asked Phineas.
"Yes," said Ferb who then realised the same thing. "They're in for a surprise when they land."
"I find it more surprising that none of us can remember any of this," said Isabella.
"What do you mean?" asked Vanessa.
"I've been searching my memory of that summer as much as I can, but I can't remember ever seeing people who looked like Sean, Rose, Terri and Kenny," said Isabella. "And I was at Phineas and Ferb's nearly every day, so I think I'd remember something like this."
"It's been twenty-five years, maybe you can't remember them," suggested Vanessa.
"It's not just that, I can't remember a time where there was a Mitch from the future. And I can recall every adventure we had with Meap," said Isabella.
"Maybe you didn't participate in this one," suggested Vanessa.
"No, she's right. I can't remember this happening either," said Phineas.
"Can you Ferb?" asked Vanessa, but Ferb shook his head.
"That's what I don't understand," said Isabella. "If this happened in the past, shouldn't we remember it?"
"Theoretically we should, but something tells me something happened to ensure we didn't. Something that I think we'll need to take care of," said Phineas.
"I also have a feeling that someone does remember this happening and is keeping quiet about it," said Ferb.
Meanwhile, Meap was lying on the couch inside recovering from his injuries. He felt guilty about keeping secrets from his friends, but he also knew this was the best way to ensure history stayed on its proper course.