A/N: Thank you so so much to everyone who reviewed and favourited and alerted. You guys are the greatest. And thank you to my beta, Altyerre, for getting this to me, even though it took three attempts to get it through.

Disclaimer: Harry Potter and the Harry Potter universe belong entirely to JKR.

Platform Nine and Three Quarters

"This is a terrible idea," Scorpius snapped, desperation having won out over tact and subtlety.

"You always say that."

"And I'm always right!"

Albus rolled his eyes.

"Just drink the potion, Scor. It's not going to hurt, I promise." I hope, he added silently to himself. He had been unable to find a description of the internal effects of the transformation process, even in the Restricted Section. He had, however, found some very disturbing pictures of the external effects, which, for several reasons, he had chosen not to share with Scorpius.

The two of them stood in an otherwise empty compartment towards the back of the Hogwarts Express, executing the most vital stage of Albus's ingenious (or moronic) plan; the switch. Scorpius, already wearing Albus's clothes, watched while Albus struggled his way into his own. Though they appeared very similar in both height and build, Scorpius was the more slender of the two, and he also preferred tighter clothing.

Turning his attention back to the murky green potion in his hand, Scorpius drew a deep, shaking breath. This was it. He could do the sensible thing, and back out, or he could go through with it, knowing that it was an outrageous deception, and that their fathers would completely flip out if they ever found out. He hadn't been particularly into the idea in the first place, so Albus would understand if he chickened out at the last minute. He wouldn't be happy about it, but he wouldn't make too big a deal of it either.

Squaring his shoulders, Scor tossed back the entire potion, shuddering. It really was every bit as vile as he had suspected. And his father was right; one day his curiosity was going to get him killed.

His stomach heaved violently, as though he were going to be sick. Gasping for air he stumbled sideways as the nausea was replaced by a burning sensation which spread throughout his body, his skin bubbling slightly as his body expanded to fill Albus's too-big clothes. His hair lengthened, falling across his face, and he watched in fascination as it darkened from pale blonde to inky black.

Across the room, the dazzling silver potion Albus had gulped down was creating the exact opposite transformation. He felt his hair shrinking back into his head as his fingers, already dramatically lighter in colour to someone who knew them well, lengthened and tapered slightly, and the calluses on his palms thinned considerably. Scor was a Quidditch-player too, but he was a Chaser to Albus's Beater.

Once the transformation was complete they checked each other over, looking for any tiny detail that might betray their switch. There weren't any.

"Just remember, this was all your idea," Scor muttered, a little startled to hear the words spoken in Albus's slightly deeper voice. "If anything goes wrong, I'm blaming you."

-x-

Albus abruptly skidded to a halt, causing Scorpius to barrel into him from behind. Scor grabbed him around the neck for balance, Albus grabbed the cage of his owl, Aconite, which had been sitting atop his own trunk which Scorpius had been pushing, Stacey Flint grabbed Scorpius's owl, Jupiter, and chaos was averted. Sort of.

"What the hell was that!?" Scorpius-as-Albus demanded, expecting an equally rude response.

Albus pointed mutely further along the platform, where two middle-aged men, one with shoulder-length blonde hair slightly receding from his forehead and the other with extremely short black hair and glasses stood deep in conversation with one another. Scorpius's—or rather, Albus's—jaw dropped. Literally.

"They're talking," he said.

"Politely," emphasised Irwin Nott, the only fourth year in their group.

"They don't even look like they want to kill each other," Albus murmured in awe.

"I thought they didn't like each other," frowned Elouise Goyle, puzzled.

Scorpius resisted rolling his eyes. How come everyone's looking at me? he wondered. It's Albus who always—Oh!

"They don't, Ellie," he responded kindly, with his best approximation of the smile Albus always gave her when he was explaining things that seemed beyond her grasp. Personally, Scorpius thought that her ditz act was a bit too perfect to be real. But then, the Malfoys had always been the suspicious kind. "That's why we're all so confused," he explained.

"Oh!" she said, with the tone of inane surprise that never failed to make Scor want to hit her, girl or not. She smiled happily at him, tucking her hand affectionately into the crook of his elbow. Scorpius could have sworn he felt his hair standing up on his head as he reminded himself that leaping backwards to get away from her would be completely out of character for Albus.

"Oh, look!" she exclaimed suddenly, tightening her hold on Scorpius's arm. "There's my family. Come on." So saying, she began to drag him away from the rest of their friends. "Daddy!" she called out.

"Elouise! Princess!" To Scor's immense relief, her father snatched her off his arm and into a crushing hug. Not that she seemed to mind.

"Hullo, Daddy," she responded, wrapping her arms around his neck. Daddy? Who calls their father 'Daddy' at sixteen? was Scor's disbelieving thought, but he got no further with it, as Elouise's brother—Beau-something-or-other—turned to greet him.

"Hey Al," he said, smiling warmly. Al? Al? What happened to 'Potter' and 'Goyle'? Scorpius wondered. What the hell was he supposed to call him now?

"Beauregard," he nodded in response, finally remembering the sixth year's name. 'Beau' would have just been too weird.

"I'll see you next year," Goyle stated, although there was a slight question in his tone that seemed wrong to Scorpius. Of course he would see Al next year; they were in the same house.

"Next year," Scor confirmed cheerfully, pretending to have missed the subtle intonation. Goyle looked at him for a moment, puzzled, and Scorpius knew that he had missed something important, but decided to let 'Al' sort it out later. Hopefully it wasn't major enough to blow the game. Now that the plan had been put into motion at last he found himself eagerly looking forward to a summer away from Malfoy Manor and his father's gloom, however guilty that made him feel.

-x-

Draco wasn't feeling particularly gloomy at the moment. Far from it, in fact. He had had time over the last few months in which to recover from the initial shock and grief caused by his wife's sudden and unexplained death, and while he was far from back to normal he at least felt able to face the world—and his son—again.

Turning away from Potter he smiled at Scorpius in welcome, hugging him in an almost unprecedented public display of affection. Scorpius took it surprisingly well, even going so far as to return the embrace. Stepping back from Draco he turned to look at Potter.

"Albus got sidetracked," he told him, and it seemed to both men that there was an odd hesitation in his voice, as though uncertain what words to use, or even what he wanted to say. Potter smiled in response.

"How are you, Scorpius?" he asked politely, although he seemed genuinely interested in the response.

"Well, thank you, sir," Scorpius replied, and again there was an awkwardness to him that made Draco knit his brows while Potter eyed him curiously for a moment.

"And how is Albus?" Potter enquired, and now the odd note was in his voice as well. What the hell is going on? Draco wondered.

"Albus is fine Dad," Albus's voice said from behind them, and they all turned to face him. "I was just talking to the Goyles," he added in an aside to Scorpius, and there was an almost Malfoy-like look of interrogation on his face as he lifted one eyebrow.

Scorpius blushed.

Draco opened his mouth to voice his bewilderment, but was cut short by a—barely—muffled shriek.

-x-

"Daddy!" shrieked the beautiful redheaded bundle of energy that had appeared suddenly in Harry Potter's arms. Scorpius, identifying her correctly as Lily Potter, third year Gryffindor Seeker and Albus's only sister, wondered why the word 'Daddy' sounded less annoying and more cute when it came out of her mouth instead of Elouise Goyle's.

Glancing at Albus out of the corner of his eye it was apparent that he didn't agree. Which meant that—in his character as her older brother—he shouldn't show that either.

"I missed you Daddy," Lily confided almost tearfully, refusing to relinquish the death grip she had around her father's neck.

"Hello to you too, Lils," Scorpius interrupted, using a fair approximation of the dry tone that Albus used when something annoyed him. Too late did he realise Albus's mistake—and his own.

"Al-al!" she pronounced with another ear-splitting shriek, and launched herself at him as well. And, damn it, she was heavy. Or perhaps she just moved fast enough that it felt that way when she bashed into you. She certainly flew like a lightweight. She also had a grip like Devil's Snare, and for the first time Scor appreciated what his friend meant when he said that his baby sister had some cruel and unusual methods of keeping him and James Potter in line.

Unfortunately, he was having a hard time remembering to act the part of annoyed older brother, and that he shouldn't be noticing how she smelt, or how soft she was. Bloody hormones.

Smiling dazzlingly at him—at her brother Scor reminded himself sharply—she released him before wrapping her arms around Harry's waist.

"I'll call you when I have more information, Potter," drawled a voice from behind them, and Scorpius turned to see his father and Albus-as-Scorpius preparing to depart.

"Please do," Harry nodded, and they smiled at each other. Not the smile of friends perhaps, but certainly the smile of allies.

Albus tried to remember what they had been talking about before he arrived, but could only recall a few words. 'Shacklebolt', 'election' and something about Malfoy never believing he would support...something...or someone perhaps.

"If it comes to that I never would have believed that I would support Per—" his father had begun to respond, before catching a glimpse of him over Draco's shoulder and falling silent so that they could greet each other.

"Come along, Scorpius," Draco said, recalling him to the present. After a moment of confusion where it looked as though Scorpius-as-Albus had forgotten his new role and was going to follow his father, Albus-as-Scorpius turned to follow instead.

"Owl me," he said over his shoulder, and Scorpius nodded. Even from a few minutes of conversation they had much to discuss between themselves.

-x-

"Okay, kids, let's find your cousins and then we can head home," Harry announced.

"Which ones?" Lily responded.

"Huh?" Albus asked involuntarily. Lily gave him a 'duh' look.

"Well, we do have five sets of them," she pointed out. As though he hadn't already known that. Although he actually seemed to have forgotten. Lucky him.

"Rosie and Hugo," Harry said, answering her initial question and ignoring the rest of the conversation with the ease of long practice. "Neither Ron nor Hermione could get the day off work, so they asked me to drop them off on the way past."

"For 'they asked' read 'Hermione instructed'," Lily stage whispered. Harry's lips twitched, but he gave no other sign of having heard her.

"You're going to have to let go of me so I can walk," he informed his clinging daughter.

"Sorry, Daddy." She wasn't. She let go of his waist and grabbed one of his hands with both of her own. "Better?"

"...and Lily taking all of Dad's attention..." Scorpius heard Albus's voice repeating in his head, and he resisted the urge to laugh. Apparently he hadn't been exaggerating. It just remained to be seen if James really hogged the shower.

-x-

"Uncle Harry!" a musical feminine voice exclaimed, and for the second time that day Scorpius watched a beautiful girl—this one a brunette, Rose Weasley, Gryffindor fifth year—launch herself tearfully into Harry Potter's arms.

Apparently his popularity with his young relatives wasn't restricted to females, as she was followed somewhat less tearfully by her brother Hugo, Ravenclaw fourth year.

And then by several other red-haired children who Scorpius gave up on identifying, but assumed to be Weasley cousins of some description.

"Harry, good to see you," announced a somewhat pompous voice, and a tall red-haired man who Scorpius decided must belong to some of the shrieking children attempted to shake Harry's hand.

"You, too, Percy," he responded, as politely as it is possible to do while being ripped limb from limb.

"Have you given any thought to...?"

"Yes, yes I have. I was talking to Draco just before, and we both agree. You are—Ouch!—the obvious choice. We just need to—Calm down, you lot—make sure that other people see that too—Ouch! Sorry Perce, I'd better go. I'll talk to you at work."

"Yes, I'd better get this ravening hoard home before their mother decides I've murdered them," the man called Percy agreed. It was only as he left, taking all the Weasley children barring Rose and Hugo with him, that Scorpius realised that all five of them were his.

Scorpius wondered whether Albus was able to keep track of all his cousins and just how much he himself would be able to bullshit his way through.

"...we do have five sets of them..." Lily had said. It was going to be a long summer.