Disclaimer: Since I'm not about to write a whole sonnet to disclaim this story, let's just leave it at "I don't own Phineas and Ferb" and move on, shall we?

Of all the days in what Isabella would come to think of as "The Phineas Summer", July 20 was, in its quiet way, one of the strangest. It began like any other: after a quick breakfast of latkes and huevos rancheros, she rushed across the street to the Flynn house, paused in front of the fence to straighten her bow and brush off her jumper, and then tripped blithely into the yard, all set to deliver her trademark catchphrase and let her favorite Phineas lead her into another mind-bending adventure.

But the words died on her lips as she looked around and realized that the yard was entirely devoid of Phineases – and, when she looked again, of Ferbs as well. The only visible soul around was the auburn-haired teenager crouching behind the bushes, pressing one ear against the drainpipe and muttering under her breath, "Come on, you little twerps, come on… I've got the phone right here, just give me something to work with…"

"Candace?" said Isabella. "What…'s going on?" (Even as she spoke the words, she felt a passing pang at how poor a substitute they were for what she really wanted to say.)

"How should I know?" Candace snapped. "Dad was reading the Daily Danville's 'This Date in History' column at the breakfast table when suddenly Phineas and Ferb got some crazy gleam in their eyes, and the next thing I knew they'd barricaded themselves in their room with a ream of notepaper and Dad's Fowler's."

Isabella blinked. "Your stepdad lets Phineas and Ferb use his fowling pieces?"

"Fowler's Rules of Modern English Usage," said Candace tartly. "Try to keep up, Campfire."

"Oh." Isabella blushed. "Right. So what do you think they're up to, then? Did you notice which column entry it was that gave them the idea?"

"Oh, of course!" said Candace, her voice oozing sarcasm. "I was just hanging onto Dad's every word, because I'm just the kind of lifeless dweeb who has nothing better to do than hear about how the Vikings besieged Sri Lanka on this date in 1304. Heaven spare me from patch-addled, twitterpated neighbor girls!"

It was beginning to dawn on Isabella that Candace was in no mood to be asked questions. Still, she ventured one more. "Well, have you heard anything through the… um… drainpipe?"

"Nothing useful," said Candace through her teeth. "Mostly, it's just been Phineas muttering in rhythm under his breath – though he did say something defensive to Ferb at one point about how nobody knows how to pronounce eisteddfod anyway. But I know they're up to something," she added defiantly, "and, as soon as they drop the slightest hint, Mom's going to hear about it so hard it'll make their heads spin. Come on, you little creeps!" she shouted into the drain. "I've already passed up cream horns with Jeremy for this; if you don't turn out to be planning something diabolical soon, I'll never speak to you again!"

It was at about this juncture that Isabella decided she'd taken up enough of Candace's time, excused herself politely, and turned and walked briskly away. She wasn't sure Candace even noticed.

Back home, she pulled the morning Daily out of the recycling and checked "This Date in History" herself, but found nothing that seemed likely to have inspired her would-be beau and his stepbrother-cum-accomplice. Yes, there was the moon landing of 1969, and Sir Edmund Hillary in the birthday section – but Phineas and Ferb had been to both the moon and the Himalayas already that summer, and there wasn't so much time left until Labor Day that they could afford to repeat themselves. Besides, why would they need Fowler's for that?

She tried calling some of their other friends – Baljeet, Buford, and even, in desperation, Irving – but none of them had any better explanations than she did. Baljeet thought that they might be writing letters of protest to the Daily for not having included the death of Bernhard Riemann; Buford, that they were building an army of papier-mâché zombies to reenact the Siege of Chartres at the Googolplex Mall; Irving… it was hard to say what Irving thought, since all Isabella heard out of him was a couple of faint mewling sounds followed by a dull thud. (Apparently this had been the first time a pretty girl had ever voluntarily spoken to him directly, and the shock had proven too much for him. Isabella apologized to his brother, and promised to send flowers to the hospital.)

So she ended up disconsolately moping about the house for most of the morning (to the alarm of her mother, who wasn't used to her daughter having nothing to do on a summer afternoon, and had to take her temperature three times to be persuaded that she wasn't ill). Yet, all the while, she felt sure that Phineas and Ferb did indeed have something terrific in the works, and that the day wouldn't end without it being revealed to her.

And so, when the doorbell rang just after three o'clock that afternoon, she leapt instantly from her bed and raced downstairs. Of course, it could have been one of their other neighbors, or UPS or the Avon lady or J*****h's Witnesses, but Isabella never even thought of those possibilities – and, sure enough, when she opened the door, she found an envelope sitting on the doorstep on which her name was written in Phineas's handwriting, and saw a flash of orange-striped shirt and green hair as two familiar figures headed down the sidewalk toward Baljeet's house.

She bent down and picked up the envelope, and examined it curiously for about half a second, wondering whether it was an invitation to some sort of San Apolinar party (eisteddfod?); then her practical side took over, and she tore it open instead of speculating further. Inside lay a single sheet of paper folded about a plain white greeting card; Isabella withdrew and unfolded it, and read as follows:

Dear Isabella: Today is the 605th birthday of Francesco "Petrarch" Petrarca, the Renaissance poet who invented sonnets. Since Ferb and I have been feeling like we've kind of neglected the humanities this summer, this seemed like the perfect opportunity to dive into the joys of traditional European verse forms. Inside this card is a sonnet we wrote especially for you (Shakespearean, not Petrarchan – sorry). Hope you like it. –Phineas.

Isabella's squeal was so piercing that her mother dropped what she was doing in the kitchen (unfortunately, as it was an ice sculpture) and came rushing out to the foyer. "Shema Yisrael!" she exclaimed, and crossed herself. "Isabella, darling, what can the matter be?"

Isabella gazed dreamily out into the middle distance, and ran a hand through her hair. "Not Isabella, Mom," she murmured. "Laura."

Mrs. Garcia-Shapiro's eyes narrowed. "Oh, this again," she said. "When you were five, it was Cordelia; now, it's Laura. Isabella, dear, there's no reason to keep being ashamed of bearing your grandmother's name; a fine woman, she was, salt of the earth. And I know I'm partly to blame, because she and I didn't always get along too good, but that's just because we started off on the wrong foot; when she showed up an hour late to our wedding rehearsal because your father had given her the address of the Danville Pet Salon, it would have taken a miracle for there to be no tension at all between…"

She went on this way for several minutes more; Isabella, who knew her mother well, instinctively went "mm-hmm" at appropriate intervals, but in fact didn't hear a word. Sonnets. Phineas was writing sonnets about her. Sonnets, those things that went, Shall I compare thee to a summer's day? – or Fair bosom fraught with virtue's richest treasure – or How do I love thee? Let me count the ways. The birthday of her life, the moment she had been dreaming of since Memorial Day, had come at last – and no wonder it had taken so long, if Phineas (the poor dear) was even now too shy, not just to say anything to her face, but even to be present when she read the words he had written. Move over, Beatrice, there was a new poet's darling on the block, whose soulful and passionate love saga would surely eclipse anything poor Dante had ever dreamed of. (Not least because, as the proud bearer of a Campfire Girls Health, Fitness, and Stamina Patch, she had no intention of dying at age 24.)

She gradually became aware that she was alone in the foyer (her mother having run out of breath, and returned to the kitchen to glue her swan back together), and that Phineas's tender expression of perpetual devotion was still sitting in her hand, unread. With racing heart, she withdrew the card and tilted back its cover, and ran her hungry eyes over the fourteen lines inscribed therein.

Fun is a thing you really have to share.
Why build a coast(er), film a classic play,
Or ride a giant bubble through the air
If you're not making someone else's day?

Someone who means the same as you by fun,
Whom your wild whims can always hope to thrill.
So nothing's not worth trying; if not one
Soul else can see the point, you know she will.

With her around, why not invent the wheel,
Farm giant ants, or brave a pirate's curse?
So, Isabella, if you ever feel
That Danville, minus you, would be no worse,

Just know that, at the best day ever's end,
It wouldn't be without you for a friend.

Isabella read this all the way through three times; then she laid the card down, closed her eyes, and was silent for a long moment. (At that same moment, across the street, Candace was likewise being rendered speechless by the sonnet her brothers had written for her – though it must be admitted that this was about all the two girls' reactions had in common.)

At last, with a deep breath, she reopened her eyes and managed a weak smile. "Well," she said aloud, "I guess it beats being the Dark Lady."