Phineas and Ferb sat under the tree in their backyard, contemplating ideas for how to spend this particular summer day. Phineas, the red-headed sibling, lazily plucked at a few strands of grass, sighing as he mulled over a few ideas. "We could build a rocket ship? Nah, we've done that already...Why don't we-? No, I think that may not be legal." The boy rolled his eyes up, thumping his head lightly against the back of the old tree. "I can't believe it! Ferb, I actually don't know what we're going to do today."

Phineas Flynn did not accept defeat, however, and just as he was about to proclaim this fact, two of his friends, Buford and Baljeet, shuffled into the family's yard. "Phineas?", Baljeet asked, eyes seeming worried, "Have you seen Isabella around? I have not seen her for nearly three days!"

Buford frowned. "Me neither! Not that I care or nothin', but still..."

Ferb shrugged and Phineas shook his head. "Come to think of it...No, I haven't seen her around. That's odd, she didn't say anything about going away." His eyes lit up a bit. "Ferb! I know what we're going to do today. Find Isabella!" As the other boys nodded their agreement, a familiar figure crossed the lawn.

"What are you four doing? And where's Isabella? Isn't SHE usually involved in your little stunts?" Candace's eyes narrowed.

Ferb blinked. Phineas smiled, pointing at the air determinedly. "That's what we're going to find out! Wanna come?"

Candace glared at them incredulously for a moment before eventually shrugging. "Alright, why not? I don't really have anything better to do anyway..."

"Great! Now let's start at her house first. I mean, it's only logical."

At Isabella's House...

Phineas, Ferb, Candace, Buford and Baljeet entered the backyard. "You know what?", Buford asked. "I don't think none 'a us ever seen this place before!"

Phineas cupped his hand to his mouth. "Isabella! Where are-"

"Get down!", a soft female voice whispered harshly, yanking the boy behind a very large bush. "I don't want my cover blown!"

The the rest of them followed suit, ducking down into the bush as well. "Isabella?", Phineas whispered, slightly shocked. "What are you doing? Where have you been the last three days?"

Isabella shushed him once more, eyes peering at him from a set of binoculars. "I'll tell you...but you have to swear not to tell anyone. And keep your voices down! She'll hear you."

Baljeet cocked his head like a confused puppy, mumbling, "Excuse me, but who is "she" and why have you been here for three days?"

Isabella gave him a dirty look. "Well, "she" is my new neighbor, and she calls herself P.B."

"Like the sandwich?", Buford asked hopefully.

Isabella face-palmed. "No. I'm not sure WHAT it stands for. But there's something...wrong with her. I think that she's not human. Here, take a look!"

She handed Phineas the binoculars and directed them towards a big hole in the fence. Through the hole and the binoculars, he saw what looked like a normal backyard, but slightly darker due to a large tree blocking a lot of the sun and a peculiar assortment of toadstools. "I don't see anything except a tree and a mushroom patch."

"That isn't an ordinary mushroom patch!", Isabella insisted. "Those are toadstools, sitting in a perfect circle!"

"And?", Candace asked incredulously, annoyed at the bizarre actions of her across-the-street neighbor.

"It's a faerie ring, lunkhead! Don't you get it?" Everyone stared at Buford a moment. The bully shrugged. "I like mythology, okay? Don't rub it in."

The little girl's arms flailed wildly. "Exactly! I think maybe my new neighbor is a faerie!"

Candace began cracking up wildly, rolling around and snorting with laughter. "A FAERIE! OH GET REAL!" Isabella tried like heck to get her to quiet down, to no avail.

"You haven't even seen what she looks like." Isabella glared at Candace.

Phineas shrugged. "We could go over and ask her if she's a faerie."

Buford shook his head. "Uh-uh, no can do. Faeries never reveal themselves to humans unless they're bound in iron chains. And anyhow, they're known fer stealing kids an' replacing them with changelings or somethin'."

Isabella looked at Phineas, adoration in her eyes. "It couldn't hurt to ask."

Buford shrugged. "Whatevah. Don't blame me if ya get stolen and ate or somethin'."

Though he left, the others didn't respond. Phineas was the first to step up to the door of the sagging house, crunching the rock from the broken steps and knocking on the splintered wood of the door. After a minute or so, it was torn open by a very lovely young woman, who, as the boys thought, could understandably be mistaken for a faerie.

P.B. Stood only about as tall as the average ten-year-old, very dainty and delicate like a China Doll, though obviously much less fragile. Her eyes were dark, dark forest green and radiated mischief, partially hidden by a pixie cut, the top of which curled and tumbled into her face. Her scarlet lips, red as the striped on her red-and-black knee-length dress, were curled into an amused smirk. Her ears were slightly pointed, with gold hoops in each of them. P.B. Peered down at the children, her face lighting up considerably. "Oh! My, hello!" Her voice was as pretty as church bells and had a pleasant Irish lilt to it. "How may I help ya children?"

Phineas stuttered a bit; he hadn't actually thought that she would be anything like a real faerie. Asking her that question would have been very embarrassing. "I...um...Hello..."

Isabella stepped up. "We noticed that you were new in the neighborhood and thought that we'd say hi!"

P.B laughed. "Ah, yes. Yer the little girl who's been watching me for the past week, right?"

Isabella's eyes went wide. P. B rolled her foresty eyes. "Ye thought I didn't notice?" P. B didn't wait for a response. "Never-mind. You're young, yer curious, no harm was done." She extended her red-nail polished hand. "I'm P. B. It's nice to meet ya."

Isabella smiled, relieved. P. B seemed very...normal, up close. Her appearance and the ring in the yard was probably a coincidence...right? "Well, I'm Isabella. These are my friends Phineas, Ferb, Baljeet and Candace."

P. B shook everyone's hands, all children but Ferb mumbling words of greeting, though his eyes bore a friendly expression. The young woman grinned at him knowingly. "It was nice to meet you all. If you want, you can cross the fence anytime to use the yard to play in. Just...stay away from those toadstools-They could be poisonous!" She looked slightly nervous as she said this, but if anybody noticed, they said nothing. This invitation was sincere, as was the warning about the toadstools. Of course, when warnings are not heeded, unexpected things can happen. This was only the beginning of something...magical.