There's been 104 days of summer vacation,
We've had a lot of fun, and sung a lot of songs,
So now it's time for a big celebration
'Cause it's been a great summer
And we thank you for comin' along!

When one adventure ended, another began

One summer later

It was the first day of a brand new summer in the city of Danville. The temperature was warm; not too hot, and not too cool. The summer breeze flew through every head of hair, and the bugs through every set of teeth passing by on bicycles. Kids were out playing in their yards, and licking popsicles. It was a city-wide celebration for the start of summer.

And of course, many kids and teenagers always kept watch on one particular backyard for whatever astounding invention might appear and disappear on it. In the beginning of last summer, the neighborhood kids were invited to a rollercoaster ride which would go on to be known as the greatest rollercoaster ever known; the coolest coaster ever.

However, the end of last summer caused some controversy and government investigation as scientific research facilities detected spikes and ruptures in the space time continuum. Luckily, the organization O.W.C.A. was able to sway them off of it as a scientific experiment gone wrong and shut down, as there were no lasting or negative effects left behind from Doofenshmirtz's Do-Over-Inator.

The dust had settled, and things were back to normal; the summer hype train was back on. School was out, so it was fun as far as the mind could imagine.

However, the events of last summer held an insanely high standard for a one Phineas and his brother Ferb. The two of them sat, leaning against their backyard tree, thinking and planning of ways to up their game for this new summer.

"Got anything, Ferb?" He asked. Ferb shook his head.

Phineas sighed and closed his eyes. "I'll admit, though, there's nothing wrong with relaxing and enjoying the fresh summer day." He exhaled, stretched his legs and toes, and smiled. He thought he could fall asleep in this condition. Ferb followed suit.

Approaching the Fletcher's house was the girl across the street, Isabella. She had a major crush on Phineas, but practically made no progress with him. Candace had Jeremy; Ferb had Vanessa, who was actually much older than him; and even Baljeet -of all people- had someone, who would be Ginger. But as hard as Isabella tried, she couldn't get anything to happen between her and Phineas.

She stopped in front of the backyard gate and sighed. "Lower your expectations this year, girl, but don't give up hope." She pushed the gate open, smiled, and said her signature phrase, "Hey Phineas! What'cha doin'?"

"Hey Isabella! We're just enjoying the summer day at the moment. Care to join us?"

"Oh, um, okay." She answered, comprehending the less exciting-than-she-expected answer. She accepted the answer, nonetheless, and took a seat in the grass beside Phineas.

There was a very peaceful time of nothing going on. Isabella actually grew to appreciate this; she wasn't sure if it was because she genuinely liked this, or if she was just spending some quiet quality time right next to Phineas. Either way, she liked enjoying it.

Then all of a sudden, a paper airplane flew into their yard and landed in front of them. Phineas noticed it, became confused, then asked, "Um, Ferb, are you making paper airplanes?"

Ferb opened his eyes and shook his head.

"Sorry, my friends!" They heard the loud voice of their Indian friend coming through their fence. "I've been working on these all morning; this is the first one that works."

"Making paper airplanes instead of doing Math in your spare time? Baljeet, are you okay?" Isabella asked.

Baljeet chuckled, "Yes, I am fine. The hobby of paper airplanes actually does involve some math and precision. You have to make each intricate fold of paper perfectly symmetrical so the wind will carry it. Then you have to take the cross breezes and wind's direction into consideration-"

Phineas snapped his fingers. "Ferb! I know what we're gonna do today!" He said with such a desperate force in his tone. Then everyone got excited.

. . .

"Paper airplanes?" Baljeet asked.

"Well, kind of." Phineas answered.

"A bit of a step down from your inventions, don't you think?"

"Remember how we finished our trip around the world in twenty-four hours?" Phineas asked.

"Yes."

"Let's make our own personally flyable paper airplanes!"

Candace was listening to music and dancing around in her room, until she felt something wrong.

"My busting senses have been activated!" She said, pulling her earbuds from her ears. She lifted her window and looked in the backyard. She saw Phineas, Ferb, Isabella, Buford, and Baljeet around some blueprints. "What are you guys doing?!" She yelled.

"Just making paper airplanes." Phineas casually and instinctively replied, to which Candace was shocked.

"You're. . . you're not inventing anything?"

"Only the perfect paper airplanes." Phineas added.

Candance hummed with content. "Well don't try pulling anything!" She said, pulling her window shut.

Phineas turned his attention back to the blueprints. "So then we'll add the rockets here-"

Meanwhile in New York, there was a quiet, but notable stir within the Sanctum Sanctorum. Doctor Strange was meditating, keeping a sense out for any mystical disturbances.

All was well until he heard a very maniacal cackle.

"Aaaah-hahahahahahaha! Aah-hahahahahahaha!" And he had a vision. An ancient power would awaken again, and he needed a new team of heroes to stop it. When he saw who, he was not only confused, but irritated. "Why can't it ever be the Avengers?" He mumbled to himself.

He looked up and saw Wong standing in the doorway with a questioning, but grumpy look on his face.

"We have work to do." Strange said.

Wong tilted his head up, hummed, then walked off. That simple hum said everything.

The gang had finished making their flyable, jet-powered "paper" airplanes. The energy in the backyard was bright, but had significantly lessened. Phineas looked over his work, the memories of the previous summer flooding to him. That last summer was -without doubt- the best time of his life. The doubt was whether he and Ferb could live up to it again. 'Another great summer of inventions?' He thought. He looked the inventions over. 'I can do better than this!'

"Phineas, are you okay?" Isabella asked.

"Huh?" He snapped out of his trance. "Oh, yeah. I just," He inhaled deeply. "Last summer was great, ya know? I did want to start this summer off a little more casually. Paper airplanes. A fun thing kids do. But I feel like if I keep on this line. . . I feel like I could do better."

"I, for one, did not expect this summer to start on an edgy note." Baljeet said.

"He's getting emotional. This must be an extended episode." Buford joked.

"This is a fanfiction, Buford. 'Episode' has a different meaning here." Baljeet corrected.

"If that's what you're worried about, then let's just do better. Let's upgrade." Isabella encouraged him.

"Hmm." Phineas rubbed his nonexistent chin and thought hard.

"Maybe we could just test run these for now?" Isabella suggested, gesturing to the planes.

Phineas grinned.

The next thing they knew, they were having a blast, flying the paper-airplane-like planes. It was no rollercoaster, but it was fun and very nostalgic to have a good time in Phineas and Ferb's backyard again.

Candace looked out her window, gasped, then screamed, "MOOOOOOOOM!"

An orange portal opened up in their backyard, and Stephen Strange stepped through it. The sight of a bunch of kids flying around a backyard in motorized paper was an initial shock to him. He didn't know what to say, or do, to get the kids down to listen to him.

Wong looked through the portal. "What's going on out there?" He asked, before widening his eyes in surprise.

"All the mystical entities and horrors we've seen, and we're shocked by flying paper airplanes." Stephen said bluntly.

"Speak for yourself." Wong retorted, trying to hide it as he backwards stepped back through the portal.

Strange scoffed at the reaction, then tried reaching the kids' attention"Um, excuse me! Hello?"

"Oh! Looks like we have a visitor." Phineas said. "Let's land these things." He, Ferb, Isabella, and Buford successfully landed their planes, but Baljeet's brakes weren't working.

"My brake isn't working!" He shouted in panic.

"You gotta give it an extra umph!" Phineas shouted up to him.

In panic, Baljeet lost control and ended up steering straight into the portal to the Sanctum Sanctorum, screaming the whole time.

From the Sanctum, Wong saw the situation unravel, and said, "Oh no you don't!" He opened a portal inside the Sanctum, and Baljeet flew in; to which he came out the other end, safely landed in the backyard next to the others.

Baljeet jumped out of the plane in good condition. "What just happened?! Where did I just fly?!" He freaked.

"Through a portal to New York." Strange answered nonchalantly.

"A, port- . . . What? Like, magic?" Baljeet asked.

"Yeah." Strange answered simply, with a simple nod of his head.

"But that is not scientific-"

"Not scientifically possible, I know; believe me, I've been there." Strange interrupted him.

"So, you're a magician?" Phineas asked.

Stephen straightened his cloak out and introduced himself. "My name is Doctor Stephen Strange. I'm a magician, keeper of things mystical, and protector of reality. I don't know why, but I need your help."

"Our help?" Phineas asked. "That seems a bit above our area of expertise."

"Fate doesn't see it that way. If you will." He finished, gesturing though the portal. "Oh, and, bring your pet."

"Perry? He's just a platypus; he doesn't do much. Speaking of which, where is Perry?" Phineas asked. "Oh, there he is." He spotted him napping by the tree. "Any particular reason he's involved?" He went over, picked him up and returned to Strange.

"All in good time." Strange replied, stepping through the portal.

"Oh wait." Phineas said. "We should clean up our project before we leave."

"We don't have a lot of time." Strange mumbled. "Allow me." He insisted, in a rush. He waved his hand and fingers around. A portal to the Mirror Dimension popped out, swooped over and took the machines there, now rendered invisible -practically non-existent- to the human eye. "Now shall we?" He gestured to the portal. He stepped through, the others following suit.

. . .

Candace swooped the door open, dragging her mom along. "See? They're right theeeee-" She dragged on, once again defeated by bad luck.

"Candace, honestly, I thought the school year would've grown you out of this."