Prompt by anthrop: "Memory Blank" AU where Sam can't convince Danny to go into the Portal, so she goes in instead.

Content warnings for enormous amounts of guilt, and a non-graphic reenactment of the Accident. Also memory loss/memories being changed/being forgotten, but that was kind of implied by the Memory Blank thing.

"No, look." Danny threw out his hands, motioning exaggeratedly, and almost hitting her in the face. "Do you realize how much of an insane stretch any of this is? But I'm playing along, aren't it? I'm willing to believe you on all this crazy stuff."

Sam narrowed her eyes at him. "You're willing to believe me on all counts, except for this one very important thing."

"The very important thing which could get him killed, dude," Tucker pointed out. He was frowning at her—had been the whole time, really. "You keep saying half-ghost, but there's absolutely no proof that that's a thing. For all we know, he was just a ghost that could look like a human."

"There was proof—"

"Proof which you can't show us," Danny interrupted her. He sighed. "Look, Sam. I'm willing to put my trust in you, alright, because there's obviously some truth to your story. But I can't— I can't walk into that Portal, knowing what it can—and will—do to me."

It felt like she had swallowed a block of ice. "Danny—"

"No, Sam." He stared her down, hard and resolute. His eyes were a clear blue. Not even a spark or hint of green. "If it's really that important, why not do it yourself? Out of all of us, you have the most experience with this, don't you?"

And, well. He had a point there. "It might be a compatibility thing, though," she said, instead of agreeing with him. "A certain amount of prior contamination necessary to stop you from getting terribly sick or dying."

Tucker scoffed. "If you really were another best friend of Danny's, and mine, you'd be contaminated as shit. You can't set foot in FentonWorks without it, let alone eat dinner at their place. There's no way that Danny is viable for this kinda thing while you're not."

"I'll let you into the lab, and I'll help you set up the machinery, if need be, but I won't do it." Danny ran a hand through his hair, shooting a quick look at Tucker. "You can even borrow my jumpsuit, if that'll make the difference, and we'll be right there. But I… I can't do it, Sam."

She never could fight against those sad eyes of his.

"I get it. I… I'll do it myself, then." She took a bracing breath. "I'll take you up on the jumpsuit, though. I don't have anything white to wear, and I'm not gonna submit my ghost form to white clothing, no matter how temporary it'll be."

That startled a laugh out of the two boys. Ah. That sounded like nostalgia.

See, the thing was, it was all Sam's fault. Not just the current situation, but all of it, really. She'd never gotten past the guilt of being the one who pushed Danny into going into the Portal. Of being the one who made Danny half-ghost.

So she'd wished that she'd never met Danny. Not just because he was infuriating, sometimes, but because she wondered… What would Danny be like, if they had never met? If she hadn't… hadn't forced him to go through all that? The Portal, becoming half-ghost, fighting to protect Amity Park…

But then when it had all come true, when she'd been forced to see, to know. She had scrabbled back. Because Danny was happy, yes, but Amity was in trouble. Amity needed its half-ghost protector, in a way they all keenly felt, yet no one knew.

Desiree could do many things, but she couldn't erase the past, not like that. So every single person in Amity knew, somewhere deep inside them, that they missed something. And every single ghost that attacked knew, too, that Amity was missing its protector.

The world screamed for the wrong to be corrected, but Sam was the only person who knew how.

And Danny told her no. He said "no" and "I can't do it", and Sam could only think of Danny's scream when he'd gone into the Portal, and found she couldn't blame him.

Yet the world screamed, and Amity Park screamed, and the citizens screamed under the endless ghost attacks.

Something had to give.

She'd forced Danny to become half-ghost once. She had been the one who forced him to endure all of that. This was… This was penance, wasn't it? A chance for her to owe up to her mistakes. To even it out.

How hard could it really be, to take down Desiree? Because that's all Sam would have to do. Take out this one ghostly enemy, and wish for everything to go back to normal.

Easy enough. Right?

The Portal stood large and looming. The tunnel behind it looked even darker and even more cavernous than Sam remembered it.

"Having second thoughts?" Tucker prodded, standing in the middle of the room with his arms crossed. "You tried to make Danny do this, you know."

"I know," she gritted back, tearing her eyes off of the empty frame. "I'm the only person who remembers, Tucker. I know exactly what I pushed him into."

"Please stop fighting, guys!" Danny fiddled with some of the Portal's controls, eyes dancing between the machinery and the photo she had, taken just before the original accident. "I get it, you two don't get along. But you've managed it before, apparently, so please manage it again."

Sam snorted. "That was all your doing, I'm afraid. You're the balancing factor, Danny."

The balancing factor between her and Tucker, the balancing factor between the human world and the Ghost Zone, the balancing factor between human and ghost in general…

Yeah. He was made for the job. She would just have to borrow it for a little while, until he could get his powers back without redoing the accident.

"I could use your jumpsuit, right, Danny?"

"Yeah, go right ahead." He fiddled with some dials. "You know where the closet is, right?"

Yes, because she'd pulled his jumpsuit out of said closet for the original accident.

"Uh huh," she said, her voice just barely wavering. "I've got it."

The look Tucker gave her was utterly unconvinced but, hey, what did he know? They were all going to forget about this once she'd beaten down Desiree, and boy, was she going to beat that ghost down.

She reached into the closet, her fingers hooking into the jumpsuit she'd seen so much in recent times. It was stark white, now, and felt rubbery against her skin. When Danny wore it, it buzzed faintly, she began to realize now. She hadn't even noticed until now, now that she was missing that.

Not for long, though. Soon enough, the buzzing would be back. First as part of her own body, and then as part of Danny's again.

Okay. That sounded a little weird. Good thing she didn't say that out loud.

"I'm gonna go upstairs to change, okay?" She tucked the jumpsuit against her chest, turning back around. "Call for me if you need me."

"Can't you just pull that on over your clothes?" Tucker asked, looking her up and down. "That's how Danny is supposed to wear it, right?"

"Yes, because he wears pants and a t-shirt." She rolled her eyes, then freed one hand to pluck at her skirt. "This? This isn't going to fit in that jumpsuit. Not comfortably, at least. Chill, I'm not gonna plant my bare ass in Danny's clothes, alright?"

Tucker stiffened, but nodded. "Gotcha."

He still hadn't warmed up to her. She supposed she couldn't blame him, not really. If some stranger showed up, suddenly, claiming to be their third best friend who'd been removed from their memories, she'd be skeptical too. Especially if that person started pushing for their mutual friend to walk himself directly into a highly dangerous machine, claiming that it would only kill them a little.

Yeah. She definitely couldn't blame Tucker. But she would need his assistance for the next bit, so hopefully he would ease up a little after she did this.

Sam went all up from the lab, and then up another floor until she reached the bathroom. The Fentons had a toilet on the lower floor, but it would be cramped and inconvenient for changing.

And… she wanted to see herself in the mirror, when she was done changing.

She took off her shoes, putting them to the side, and took off her skirt, leaving her in her shirt and leggings. She made a face, contemplating that. Her shirt would definitely roll up in the jumpsuit, and her leggings would chafe like hell. The jumpsuit was Danny's, and they weren't the exact same size.

Underwear would be fine, right? It's not like he would be wearing this jumpsuit, anyway. Desiree could revert him back to Phantom, and none of this would've happened. It wasn't weird.

Sam stripped down to her underwear quickly, half folding her clothes before dropping them aside. She then reached for the jumpsuit, stuck her legs through it, but paused with it hanging off of her hips. The material was tight and clingy, sticking to her legs like a second skin.

No hesitation, Sam. Danny didn't get to hesitate, either, when you made him do all this.

The body of the jumpsuit was pulled up, and she wrestled her arms through the sleeves, too. Zipped it up right across her front, ignoring the increased tightness around her chest.

Huh. She really was a little bigger than Danny. Funny, the things you discover when you put on someone else's clothes.

She met her eyes in the mirror, then made a face. Right. Peeled the sticker of Jack Fenton's face off of her chest.

Better. But not quite there yet. Like this, she was just… just doing exactly what Danny did. Phantom 2.0. That wasn't… That wasn't Sam's thing. Exactly replicating someone else.

She looked down at the boots and gloves that she'd laid to the side. Then to her own stack of clothes. Now there was an idea…

Oh, she was so glad that she had put on socks today. Her boots grounded her the moment she put them back on, solid and heavy. The Portal would dye them white for her ghost form, but that was alright. A little white would make her jumpsuit look even blacker, just like it did for Danny.

The boots helped, made her feel a little more unique, but there had to be more she could change up. Right?

She met her own eyes in the mirror again. Bit her lip in thought. Bent down again to dig through her skirt's pockets until she unearthed a purple hair tie, and swapped it for the green one she usually had in. There. Now it would match her eyes in her ghost form.

Nothing else came to mind, though. She could hardly put on regular clothes over the jumpsuit, and she didn't want to risk messing with the jumpsuit itself too much. They had never quite concluded how vital it was to Danny's half-ghost-ness.

Actually, they never quite figured out any of that. For all she knew the Portal could kill her the moment she hit the switch.

But the world, their entire reality, still screamed for its missing half-ghost. And if it wasn't going to let her convince Danny, well, it would just have to settle for her.

Sam bent down to pick up her abandoned clothes, her fingers running along the purple skull on her shirt, and paused. Actually…

Danny's room was still the same barely organized mess she was used to, thankfully. It took her barely a minute to dig out some scissors, which she took back into the bathroom. Out of her backpack, which she'd luckily taken up with her, Sam pulled a needle and some thread.

The skull was cut out of her shirt, and the jumpsuit taken off again. With some overly hasty stabs of her needle, Sam sewed the cloth straight onto the chest of the jumpsuit. It wasn't very well attached, but she would just hope that it would stick in her ghost form.

Redressing herself, Sam met her own eye in the mirror for the third time. Purple eyes, purple hair tie, purple skull on her chest, like a superhero logo. Only this logo was deliciously ironic, a skull for a ghost.

Black boots, heavy and square, solid in the nose. Black gloves, tight and rubbery, but just as shiny as the boots. Black hair, loose without getting in her face, her ponytail in the back.

White jumpsuit. Like fresh fallen snow, like the innocence she'd lost when she watched Danny die due to her own persistence.

"Good," she decided out-loud, listening to her voice echo in the small space. "Let's get this over with."

When she made it back to the lab, Danny and Tucker had moved to one of the mostly-empty lab tables, bent over it. They looked up at the sound of her boots, allowing Sam to see that they were bent over her photo album.

"Ready?" Danny asked, pushing himself up entirely. He paused, then frowned at her. "What did you do with my jumpsuit?"

"Added a bit of personality." She shrugged, dumping her backpack next to Tucker. "I don't want to be Phantom 2.0. That's not my thing, that's yours."

"Or so you keep saying," Tucker scoffed. He shook his head when she glared at him. "Chill. Your photo album is crazy, but it's kinda convincing. You don't look like the type to be able to pull off such convincing photoshops."

"Thanks." She combed a hand through her hair, the gloves feeling odd against the skin of her head. "Is the Portal ready?"

"As ready as it'll ever be, I guess." Danny turned to look at it, his mouth thinning. "Are you sure that this will be okay?"

No. No, because it wouldn't be. She could only be sure of it if it was Danny going in, and even that would not be okay, not in any measure of the word.

"Yeah," she told him, as encouraging as she could. "Yeah, I think it'll be fine."

"Go for it, then." Danny stepped to the side of the Portal, and Tucker wandered over to the other side of it. "We'll be here for you."

She nodded at the both of them, standing in front of the Portal once more. Took a deep bracing breath. Walked in, step by step.

Her hand found the button on the Portal's inside like it was drawn to it. She hesitated for just a single moment, a single lingering second.

The button clicked underneath her black-gloved hand, and everything went green, then white, then black. A single moment, suspended for infinity, the shortest and the longest second of her life.

Sam heard screaming, haunting and echoing. Some of it, she knew, was hers. But she could swear that she heard, layered underneath it, Danny's own dying scream.

It was like reality warped itself around her, through her. Everything shifted, like someone stirred the milkshake of reality.

The floor of the lab was hard underneath her hands, but stable. The light was blinding. Two pairs of warm hands patted her on her shoulders, her arms, her back. Their voices were buzzing in her ears, sound with no meaning.

She groaned, pressing her head against the cool floor. It felt like every molecule of her body hurt. She felt cold-hot-cold, simultaneously energized and dead-tired. Her heart alternated between racing and faltering, a humming in her chest not quite synced up with the thumping.

"Sam?" Danny asked, and the worry in his voice made her guilt spike all over again. "Sam, are you alright? You didn't say—"

"Might've repressed this part," she muttered back. She braced her hands against the floor, pushing herself up into a sitting position. Ooh. Woozy. "You didn't get hit, right?"

"Shit, dude, you really went for it." Tucker laughed, dry and humorless. "You really are crazy, Sam, no offense."

"None taken." She certainly felt crazy. "Ugh. I'm starting to think that Danny left a lot out when he told me and Tucker about what the accident was like for him."

Tucker snorted, a little more humorously. "That sounds like Danny, yeah."

"Hey!" Danny puffed himself up, the picture of indignance. "That's not true!"

"So if you were hurting, but you could keep it a secret from your best friends, you would tell us?" Sam prodded, working her feet under herself so she could stand up. She felt light as air. No wonder that Danny usually flew when he was in ghost form.

He huffed, but didn't respond. Yeah, that's what she thought.

Sam pushed herself all the way up until she was standing. She teetered for a moment, but Danny and Tucker reached out to catch her, standing on either side of her.

"Thanks," she managed, feeling her core splutter in her chest. "I think I should shift back to human form."

"Okay," Tucker said, encouragingly. "Go on, then. Don't let us stop you."

She made a face at him. "I… don't know how."

Luckily her body did know. Or maybe her core just gave up on holding her ghost form.

Her core jerked in her chest, and light haloed around her. Swept over her body, washing away the black jumpsuit and replacing it with the white one again.

"Oh, well, there we go," she said, shrugging lightly. "Problem solved."

"For some reason, I thought the jumpsuit was going to magically stop existing." Danny shook his head, clapping her on the shoulder. "Well, come on, let's get you back into your normal clothes."

Sam laughed a little awkwardly. "Ha, yeah, uh. Can I borrow a shirt? I might've cut the skull out of mine."

Danny shot her a flat look. "Yeah, sure. You already got my jumpsuit, what's a shirt compared to that?"

Sam crouched on the hill. On either side of her, Danny and Tucker did the same. Both held an ecto-gun, and she'd given them a quick training course on shooting those, but…

But it would come down to her, now. It was up to her to save the day.

Her heart thumped, her core whirring up a storm in her chest. It hadn't even been a day since the reenactment, and here they were. Facing down Desiree, before she got too powerful for any of them to stop.

With a mental tug on her core, Sam summoned the rings of light to return her to her ghost form. They danced over her, until she was left in the color-shifted outfit she'd put together. Danny's jumpsuit, deep black, contrasted against the white gloves and matching combat boots. Her hair, just as white as Danny's had been, whispy and drifting in the wind. Her ponytail flared like a flame, the hair tie a bright cyan. The same cyan as her eyes, as the skull on her chest.

"We'll be right by your side," Danny said, and he grinned as the ecto-gun in his hands buzzed with power. "Go when you're ready."

Ready? Ready? She would never be ready, not really. Not in a million years. The core in her chest was still an alien sensation, leaking power when she didn't want it to, yet refusing to give her any when she did want it. It wasn't hers. It shouldn't be in her chest, it should be in Danny's.

But she was going to fix that, now. Just once, it would be up to her. And then everything could go back to normal.

"Let's go, then." Sam pushed herself up onto her feet. "Before she gets too powerful."

She jumped up into the air, forcing herself to forget gravity. To stay afloat like it's the most natural thing in the world.

Shockingly, that actually worked.

Well, time for step two. Controlled flight. She's seen Danny do it a ton of times, and has even flown with him. How hard could it be to replicate that?

Her core kicked up a notch, but she remained steady in the air. It wasn't fast, but it was flight. It brought her to Desiree, and that's all Sam wanted from it.

"Desiree!" she shouted, once she evened out with the ghost.

The genie whirled around, her blue tail curling. Cocked her head at Sam. "Oh, hello, young one. I'm afraid you have the advantage of me, because I don't know your name."

"Sam?" she bit at the ghost, incredulously. "Sam Manson? You must've heard it at some point while you were stalking me, hoping that I would accidentally wish for something to ruin Danny?"

Desiree blinked. Her expression was blank, like she didn't recognize any of this. "I think you must have me confused with someone else, Sam. I can say with certainty that I've never met you before in my life."

"What, because I'm half-ghost now? Because I'm here as a ghost, instead of a human?!" Sam felt anger boil in her chest, red-hot and vicious. It wasn't good, she knew. She had to rational, not emotional. But if she didn't listen to her anger, she would hear the doubt underneath it.

And she couldn't bear listening to the doubt. Not yet.

"Half-ghost?" Desiree repeated, looking intrigued. No, no, no! "Those are a rare sight, but, no, I doubt that that is it." The ghost tilted her head, frowning a little. "You seem upset. What is troubling you?"

"What's troubling me?" Sam echoed sharply. "What's bothering me?! This! This is bothering me! You fulfilled a wish of mine, just a few days ago, and I want to undo it! But you don't seem to remember any of it, either! Aren't you immune to your own granted wishes?!"

"No, certainly not." Desiree coiled her tail, gazing down at Sam. "Although it is odd that you remember it, yet I do not. Can you repeat it for me?"

Sam growled, feeling her core hum with increased speed, increased force. "No, but I can paraphrase. I asked you to make it so that Danny and I never met. What's weird about that, huh?"

"Wishes like that could have a huge area of effect." Desiree seemed content to ignore Sam's anger, the snarling of her core. "Although it seems odd that it would have affected me, too. Fulfilling your wish should've split reality, creating a separate track, which could be merged back onto the original line when the wish gets broken."

"Okay, so break it!" Sam snapped back, her hands balling into fists, even though she didn't want to get physical. Not anymore. "Danny's down there, the pale kid. He is supposed to be the half-ghost, here, confronting you. Fix it!"

Desiree paused, moving to stare Sam right in the eye. "You switched places?"

"I— yeah?" Sam blinked, momentarily stunned, before snapping back into focus. "Why? What does it matter? I just want you to fix this! I'll wish for it, if I have to!"

"That won't help." Desiree shook her head, her black hair moving like a wave. "You have irreversibly changed this reality."

It felt like Sam had swallowed ice. Like her heart—and her core—had frozen over. "What? But— We needed a half-ghost here to confront you, and Danny wouldn't do it!"

"I am sorry," Desiree said, and damn her, she really did sound sorry. "There are limits to my powers, too. I created a simple split, which could be reversed easily. A 'what if'. You might've noticed it, yourself, with your knowledge of the true timeline."

Sam nodded, slowly, reluctantly. "I… It felt like reality was screaming for… for its protector. That Amity needed its half-ghost back."

"And now it has that." Desiree gestured over at Sam. "Reality wanted its half-ghost. It had a hole in its very being. By becoming a half-ghost yourself, instead of the one who was before, you've reshaped that hole. And now the original will no longer fit."

"No." Sam shook her head. It couldn't be. She refused. "No, I can't… That can't be! It was supposed to be a temporary solution, until you turned it back to normal!"

"You've permanently split the timelines. I can't help you any further." Desiree's green hand patted Sam on the shoulder, suddenly. "If it would make you feel better, you can wish for it. As proof."

"I…" Sam sighed, running a hand through her hair. "No, there's no point. But can't I— Can't I wish for the same thing as the first time? Just do it over again?"

Desiree frowned. It was a sad frown, and maybe a little disappointed, too. "You've already tried convincing your friend once. What makes you so sure you'll be able to do it on a next attempt?"

Sam opened her mouth to reply, but Desiree held out her hand. "It doesn't matter, because I can't do it. This timeline is already fragile. Splitting it again could shatter it entirely."

"And what would that do?" Her heart thudded so hard that Sam was sure it was ramming against her ribs. "If the timeline shattered?"

"All of this," Desiree made a large sweeping gesture, passing over Sam, over Danny and Tucker below them, over Paulina's party in the distance, "All of this would be gone forever. Not a single soul would remain. Not ghosts, not humans, not even the slightest speck of it. You would risk the permanent non-existence of everyone and everything here."

Desiree's eyes grew sad, and she swept some of Sam's hair out of her face. "I ask you this, Sam. Is this reality really so much worse than your original, that you feel you must risk so much to get it back?"

Sam swallowed. Her throat felt stoppered up and dry.

Penance, her mind shouted at her. It is your life now, instead of Danny's, that is forever ruined.

"No," she said to Desiree. Her voice wavered, and her eyes felt wet, but she didn't cry. "No, I guess that it's… fair. Reasonable."

The ghost frowned at her like the reply didn't quite make sense, but she nodded. "You have a lot on your mind, Sam. I won't fight you. But if you want the fulfilled wishes to go…"

"Yeah, I got it." She unclipped the Thermos from her belt, uncapping it. "Desiree, I wish that you would go into this Thermos, and that all fulfilled wishes were undone."

"So you have wished it," Desiree said, her smile soft and sad, "so shall it be."

And, without another word, Desiree was sucked into the Thermos. All around them, wishes fell apart, returning to their original forms.

Sam waited until everything settled down. No change. She sighed, but lowered herself to the ground again.

The moment she landed, Danny and Tucker were by her side.

"What happened?" Tucker asked, watching her put the Thermos away again. "I thought you were going to fight her?"

"Wasn't something supposed to change?" Danny frowned, glancing around them. "It looks like every wish was undone, except…"

"It's fine, it's done." Sam released her tight hold on her core, and shifted back to her human form. "This is… This is it. We'll just have to make new memories."

Now Tucker frowned at her as well. "And the… the half-ghost thing?"

"Don't worry about it," she insisted, wrapping her arms around them to draw them in for a hug. "Everything is as it should be."

Don't be guilty, she thought, projecting the thought out to them. Don't continue the cycle of guilt.