If you watch an amv i posted on my account you would understand this story more, it base off it.
The amv can be in fact found under the name thedoginvader2, yes i made that as will as this story,
Phineas's PAIN!
Phineas put the final touch on the new thing he was building. He wanted to try it as soon as he could, but he needed to wait for Ferb who was getting some food for the testing. The thing he build was a other space ship for he plan to go to space once more.
Ferb rush in, and ran up a small road that spin around the space ship. He jumped in beside Phineas and grubbed what look like a sandwich. He put one in a cup holder and give the other to Phineas. Phineas smile a thanks, and put it in his own cup holder.
"So are we ready to take off?" Phineas asked as he tie himself in.
Ferb nodded. Phineas waited for Ferb to lock himself in, and close the door. Then he started the ship, the ship rock left and right, and then bust itself into the air.
"So Ferb what should we see today?" Phineas asked, as he look out a window. He saw that the earth was now really small. But not to small.
"I think we should SO NOT SEE THAT ROCK THAT IS COMING AT US!" He yelp.
Phineas gasp as he notice a big rock coming to them.
If it hit it would blow up the ship maybe even kill them. Phineas quickly move the wheel left and out of the way. He fall to the floor and sigh.
"We almost got hit!" he said.
"ALMOST! WE DID!" Ferb said, he pointed at one of the wings out the window, it was half gone and on fire.
"Ferb! Get us back to Earth!" Phineas yelp.
Ferb nodded and grubbed the wheel he flip it down. The ship nose pointed at Earth, then two laser came out of the bottom, and it bust to Earth at lighten speed.
Phineas hold on for dear life, as the ship move faster and faster closer and closer to there home! They where going to crush land.
"I don't want to die!" Phineas said.
The ship then crush into the backyard. Isabella one of Phineas friends, ran into the backyard and gasp she quickly started to move parts of the ship, then she found Phineas and Ferb, she sigh when she notice they where okay and a wake at the less.
"Phineas!" she said.
"Can you hear me?" She asked.
"Yup in pain but beside that I'm A OKAY." he said.
"Ferb?" she asked.
"Same." He said.
Petty much the story is show in the amv Phineas builds something. Happiness won't keep him out of something, and then he tries to fool Isabella into some kind of dark side thing. I still don't have the full story but it in the amv.