(A/N: Alright, we got some readers. Cool. I'm always a little concerned when I do crossover stories since they don't get as much attention as, well, non-crossover stories, but this looks like a good start. So, as a belated present for you all, here's the next chapter. Time to find out how Bill came back and just how he ended up in Marcy's head.)

Disclaimer: I own nothing.

Chapter 2: Bill 2.0

Anne and Sasha stared at Marcy in concerned bewilderment. If the look on her face wasn't unsettling enough, the distorted voice that came out of her mouth certainly was, and the two of them exchanged an uneasy look.

"Um… Marcy, you feeling ok?" Anne asked hesitantly.

Still grinning, Marcy pushed herself to her feet. "Yeah, yeah, feeling great, toots."

Sasha's eyes widened. "Whoa, Marcy, your voice is… sounding a little weird."

Marcy let out a bark of laughter. "You think that's weird? You haven't seen anything yet."

She pushed past the two of them and began walking away, but Anne quickly circled around her and placed her hands on Marcy's shoulders to stop her. "Whoa, Marcy, hold up. You took a pretty nasty hit to your head, so you probably shouldn't move right n– Oh man, your pupils look all wiggly, and your eyes are kind of yellow. I think you have a concussion. Let me get medic here and–"

Marcy's hand suddenly shot out and snatched the walkie-talkie out of Anne's hand. "Yeah, that won't be necessary. Everything is fine."

She then squeezed the walkie-talkie, displaying a startling show of strength as she crushed it in her grip and then dropped it with a laugh.

"Hey, what the heck, Mar-Mar!?" Anne exclaimed as she motioned to the crushed device. "That's gonna cone out of my paycheck!"

Marcy openly laughed at that. "It's funny how you still think I'm your friend, Blue Gem; I'm not exactly being subtle about it."

As Anne continued to give Marcy a look of outrage and bewilderment, Sasha came up behind her and placed a hand on her shoulder. "Anne, I don't think that's Marcy."

Throwing back her head, Marcy let out another laugh. "Oh, wow, what gave it away? Maybe this?"

She raised her hands up and began to float in the air. Anne and Sasha took startled steps back as they stared up at her in astonishment. Objects from their surroundings began rising up as well and began rotating around Marcy as she proceeded to laugh.

Both Anne and Marcy cringed away from the display of power. "What's going on?" the former exclaimed. "Who are you? Where's Marcy?"

More laughter, followed by an even more deranged grin. "Sorry, sweetheart, but Marcy's not here right now. I guess you can say she's sleeping. But you can call me Bill Cipher."

Anne's brow furrowed at the familiar name, and she tried to remember where she heard it from. It came to her a few moments later. "Wait, Bill Cipher? The triangle guy Marcy said she'd been dreaming about?"

Marcy, no, Bill laughed some more. "Yeah, sure, 'the triangle guy'. Try godly, interdimensional, cosmic being of pure energy." He lifted a hand, Marcy's hand, and snapped his fingers, and a blue flame appeared in his palm. "And it looks like I even have access to some of my powers. That's unexpected, but useful. Guess it's because I'm actually in her head instead of just controlling her body. It's only a fraction of my real power, but it's still a start."

Sasha pointed up at him. "That doesn't tell us anything! What the heck are you, and what do you want with Marcy? Give her back!"

Bill held up his hands. "Whoa, whoa, chill out, Pink Gem. To answer your question though, I guess the closest thing you could consider me to be is a dream demon, and that's just due to a lack of terminology. As for your friend, you can have her back once I'm done with her. But by then, it won't even matter."

"That still doesn't explain anything!" Anne exclaimed, throwing her hands into the air. "What are you going to do with our friend? How did you even get into her head?"

Bill nonchalantly tapped his chin. "Hmm… Well, I guess it is a story worth sharing. Especially since it relates to you two. Alright, take a seat, ladies, because you're going to love this."

From behind Anne and Sasha, a bench flew over to them. It crashed into them from behind, forcing them to sit, before lifting them up into the air. Bill continued to hover, but then leaned back as he reclined in the air.

"Like I said, I'm an interdimensional being from another dimension on another plain of existence. After destroying my universe, I spent the last trillion years trying to break out of it into other realms to keep the party going. Unfortunately, I couldn't just casually dimension hop. Needed someone on the other side to help me open a portal so I could unleash my weirdness."

A feeling of dread coiled in Anne's stomach, and her immediate reaction was denial. "You're lying. Marcy would never do something so irresponsible."

"Again," Sasha whispered to her.

"Again," Anne reluctantly admitted. "Not after she…"

The smile on Bill's face became almost mocking. "After she got the three of you lost in Amphibia on purpose?"

"It wasn't on purpose," Anne snapped. "She didn't think the Calamity Box would actually work; it was just a wishful thinking fantasy she was trying to play out."

"Whatever makes you feel better, Blue Gem. But you're right, she didn't invite me into her head. However, this isn't the only universe out there, as you should know. I've reached out to a ton of different people who got involved with the occult who have managed to summon me. And about two or three thousand years ago, I was able to get into the head of a brilliant-minded newt in your favorite frog-filled world. I made a deal with him so I could go in and out of his head whenever I wanted to try and get him to open a portal for me to come through."

"What's any of this have to do with Marcy?" Sasha demanded, wishing she could talk to Maddie, the frog practitioner of witchcraft. If this Bill person was indeed part of the occult, then Maddie would be the person to ask about him.

Bill let out a laugh. "Oh, we're getting there. Trust me, this is going to be a great story. I totally thought I had my ticket out of my dead dimension with this newt. I mean, they were already using the Calamity Box to take over other worlds in other realms. Surely they could build a portal that could lead to my dimension."

He sighed loudly, now looking annoyed. "Unfortunately, I made a small miscalculation. As you should recall, Newtopia was uploading copies of the minds of their leaders and most brilliant of newts into this collective consciousness in some super computer they called the Core. And the newt whose head I was going in and out of was one of them. When the time came for his mind to be uploaded into the Core, I was in it."

Anne's eyes widened. "Oh, cruuuuud," she muttered, suddenly feeling as if she knew where this was going.

A sneer crossed Bill's face. "You starting to figure it out? That's right, since I was in that newt's head, I had a copy of myself uploaded into the Core as well. I figured it would be beneficial to have a second me that could help bring Bill-Prime into the world on the other end. But like I said, I miscalculated. Turns out with all those brainy minds interacting with my copy within the Core, they were able to figure out my plans for multiversal conquest. So the newt whose head I was inhabiting severed all ties with me while the combination of all the minds in the Core were able to suppress my copy; meaning me, I was the copy."

He shrugged. "So that plan turned out to be another dead-end. OG Bill went back to the drawing board of trying to escape his dimension while I, Bill 2.0, was stuck in the depths of the Core's mental prison for a few thousand years. That is, until ten years ago when I finally found a way out."

Sasha inhaled as the pieces began clicking into place for her too. "Darcy…" she whispered referring to the name the Core had used when it was hooked up to Marcy.

Bill pointed at her. "Bingo, Pink Gem. Having the Core hook up to your friend allowed me to escape my mental prison in the Core and get into Marcy's head. From there, I laid low and continued to bide my time. When you severed her connection to the Core, that may have freed her from it, but I was in her head now, slowly getting stronger and stronger over the past ten years until I was finally able to take over a few minutes ago. That little head bonk was just what I needed to overpower little Miss Green Gem's mind. And now, here I am. Large and in charge."

Anne and Sasha stared in disbelief. This creature, this… mind parasite, had been in Marcy's head ever since she had been hooked up to the Core. That was… unsettling didn't seem like an appropriate enough of a word. And now he had taken over her completely? Was Marcy even aware of what was happening right now?

First Sasha, then Anne, hopped down from the bench and glared up at Bill. "So what's your plan now?" the former demanded. "To create a portal so the real you can invade the world?"

Looking annoyed, Bill crossed his arms and averted his eyes. "Uch, no. Unfortunately, that ship has sailed. The original Bill already invaded this world several years ago, but he was defeated. All that's left of him is a statue of his body. And me of course, but I'm just a copy of his mind. Guess that's why my powers are so limited."

"Well, don't get comfortable," Anne told him. "We've saved Marcy once before and we'll save her again."

Bill rolled his eyes. "Uch, relax, will you. I already told you that you can have your friend back. Once I gain a body of my own that is." A cunning grin spread across his face. "And I know just how to do it."

Anne cocked her head to the side as the possibility of a peaceful solution occurred to her. "You want my friends Ally and Jess to build a robot body for you?"

Bill looked appalled at the suggestion. "A robot body? Bleh, no thanks. I already have a body in mind. All I have to do is get to the statue of the original Bill Cipher. Once I reach that, not only will I be able to take it over to get a body of my own, but I'll return to full power. And in this world, free of my dimension. Then multiverse conquest will be mine!"

He began laughing maniacally. It was disturbing to see such a look on the usually cheerful Marcy's face. One thing was for sure though, if this Bill person managed to get a body, it wouldn't be good. Anne and Sasha had no idea what would happen, but they did the whole multiverse invasion thing before, and it hadn't been fun the first time.

"You're crazy if you think we're just going to stand by and let you take over our world!" Sasha declared.

Anne stepped up beside her. "That's right. If the other you was already beaten, then this one can be as well." She blinked as a thought occurred to her. "Wait, how do you even know what happened to the other Bill anyway?"

This just made Bill grin. "Aside from the fact that I can see through anything that bears my image," he drew the shape of a triangle with his fingers, "do you really think an all-powerful being like me wouldn't know what happened to my other self? Sorry, sweetie, but I see everything." His voice became deep and distorted for a moment. "As for stopping me, good luck. The only reason OG me was defeated was because he was tricked into entering someone's mind, which was then erased while he was inside it, so he was erased too. Regardless, that's not a mistake I plan to make a second time. Try and stand in my way, and you'll be sorry."

Sasha pointed at him. "No, you'll be sorry. No one messes with our friend."

"Yeah," Anne agreed. "And you said it yourself, you only have a fraction of your real power."

Bill nonchalantly shrugged. "Maybe so, but seeing as my real power allows me to pretty much control all of reality, a fraction of my power is more than enough to deal with anyone who challenges me. Watch."

He lifted his hand and Anne and Sasha were lifted into the air. With a sneer, he began circling his index finger, and the two of them began rapidly spinning around in the air.

"Stop it!" Sasha cried. "I'm going to be sick! I'm going to be sick! I'm going to be sick!"

Bill laughed and flicked his finger. The two girls went flying, crashing into bushes. Both had dizzy swirls in their eyes, emitting unpleasant moans. Sasha's face suddenly turned green, and her hand flew to her mouth with a muffled gag as her cheeks bloated. She managed to hold in whatever came up though and swallowed it down. Her hand fell away from her mouth with a sickening groan, but a moment later, whatever went down came right back up, and she just barely managed to turn to the side before vomiting right next to Anne.

The sudden display seemed to snap Anne out of her dizzy spell and she looked down at her blonde friend in disgust. "Come on, dude! Seriously!?"

Sasha just grumbled in response as Bill openly laughed. "It's funny how pathetic you are. And to think that you were the ones prophesized to save Amphibia. Well, you won't be saving anyone else. So stay out of my way if you know what's good for you, because I've got a date with destiny. Look out, Gravity Falls, here I come!"

Then, still laughing, he took off with Marcy's body, flying through the air like some kind of superhero. Still feeling dizzy and disorientated, Anne forced herself to stand up on wobbly feet and stumbled after him. She didn't get far though before collapsing.

"Come back, you… body snatching person," she called after him, but Bill was already far off in the distance, well out of range to hear her.

Behind her, Sasha struggled to get to her feet as well. "We have to…" Her cheeks bloated again and she quickly turned around and vomited in the bushes a second time before slowly looking back at Anne. "We have to stop him. I don't know what he's capable of at full power, but I don't think we want to find out."

Anne glanced back at her with a glare. "Dude, what about Marcy? That… thing just body-jacked her."

Sasha rolled her eyes, a mistake considering her dizziness. "Of course I'm worried about Marcy, but from the sound of it, she's not in danger right now. He needs her body to get his body…. Or his other self's body. I don't know, the whole thing is weird! The point is, as long as he needs her, he won't hurt her. But once he gets his body, she'll be disposable. And if he's really as powerful as he says he is, then we're all going to be in trouble. We've got to stop him before he gets his body."

Anne threw her arms up in frustration. "How!? He's already long gone, and we have no idea where he's going!"

Sasha shook off the last of her dizziness. "He said something towards the end there, didn't he?"

Anne blinked. "What, you mean Gravity Falls? I don't even know what that is! Is it a place? The name of something? Some weird power he has?"

"Calm down, Anne," Sasha scolded, her natural leadership skills surfacing and her tactical mind from her time leading the resistance in Amphibia coming back to her. She began pacing as she recounted everything they had just learned. "We won't do Marcy any good if we panic. Now, let's try and access the situation. We have this interdimensional mind-clone of a super powerful being that got into Marcy's head through the Core. This Bill guy wants to get to the statue of his original self in order to gain a body, and when he does, he's planning to take over the multiverse, and we can't let that happen."

She stopped pacing and looked back at Anne. "Based on what he said, it sounds like Gravity Falls is a place. That's probably where the statue he needs is. But I have no idea where that is or how to get there."

Anne's face suddenly lit up. "That's ok. At times like this, we have…" she dramatically held up her phone, "the internet!" She immediately began searching. "Ok, let's see… According to this, Gravity Falls is located in… Oregon."

Sasha threw her hands up. "Great! Do you know how long it will take to drive there from L.A.? And as we just saw, Bill can fly! There's no way we can get there before him."

Anne's face it up. "Maybe we can. He may be able to fly, but I doubt he can fly faster than a plane. Maybe we can get there before him."

Sasha crossed her arms. "Not with how long it takes to get through airport security," she muttered under her breath.

"What?" Anne asked, not hearing.

"Nothing. How long does a flight from here to Oregon take?"

"Hold on, let me check… Ok, the flight time is approximately an hour and fifty minutes. We can probably beat him there."

Sasha considered this for a few moments. "Yeah, maybe. But even if we do, how are we going to stop him? He literally tossed us around like ragdolls. Without even touching us! I mean we faced Andrias and the Core, but we could physically fight them. How are we supposed to combat against magic though?"

Anne didn't have an answer to that. Sasha was right, the Core and Andrias had highly advanced technology, but not magic. Well, the Calamity Box was magic, but that only acted as a power source. What Bill had just done to her and Sasha, not to mention the other power he displayed, how could they fight against that? And what else was he capable of? No, they were going to need something more. It would be pointless to get to Gravity Falls before Bill if they had no way to stop him.

A thought suddenly occurred to her, but had her hesitating, and she began to worry her bottom between her teeth. Perhaps there was a to fight against Bill, but it would require her to not only break a promise, but reveal a secret, because she knew that Sasha wasn't going to let her go after Marcy alone.

"Anne, I know that look," Sasha remarked. "What are you thinking?"

Anne let out a sigh as she came to a decision. There was no choice. Marcy was in danger and the world was at stake. She was sure that she would be forgiven for breaking her promise in light of that. "Ok. I think I might know a way we can stop Bill, but we're going to need help."

Sasha nodded. "I'm ready for anything. What do we need to do?"

"It'll take too long to explain now." She motioned for Sasha to follow her. "Come on, I'll tell you on the way."

(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)-(-)

"What do you mean you're friends with a witch!?" Sasha exclaimed, nearly crashing the car in the process.

"Dude, watch the road!" Anne cried from the passenger seat. And once Sasha was back in the correct lane, she went back to the lengthy text she was typing.

"Sorry," Sasha muttered. "But what do you mean you're friends with a witch? Like, a witch like Maddie from Amphibia? They have those in this world?"

Anne wobbled her head. "Well, yes and no. It's kind of a long story."

"Spill, Boonchuy."

A sigh escaped her. "Ok, look, back when we were in Amphibia, before you and I met up for the first time, the Plantars and I met her. It was really freaky. The Plantars and I were running from this bug monster, and we ran right into this girl about our age back then. She had just arrived in Amphibia through this portal she created with her, I guess, magic teacher. Turns out she had gotten stuck in the demon realm and was trying to create a portal back to the human realm."

Sasha raised an eyebrow at her. "The demon realm? You mean Hell?"

"No, just another alternate world in another dimension where magic exists and these witches and demon creatures live on top of a giant corpse called the Boiling Isles."

Sasha gave her a strange look, as if she were wondering if Anne was making all this up or not. "A giant corpse?"

"Uh-huh, a giant corpse."

"And this place is called the demon realm? Are you sure it wasn't Hell?"

"It's not Hell!" Anne exclaimed, throwing her hands in the air. "Look, the giant corpse belonged to this super powerful near god-like creature called a Titan, whose magic was so great that life emerged from its rotting carcass and evolved and learned how to utilize magic."

Sasha narrowed her eyes and returned her attention to the road. "Sure sounds like Hell."

"Whatever, dude," Anne grumbled. "Anyway, the portal she created wasn't stable, so we didn't get to hang out long before it started to collapse, so she and her teacher went back through. She eventually found a way to return to the human world though, but it was after we stopped the Newtopian invasion. At some point, she saw the news reports about the invasion and recognized me from them."

Sasha scoffed. "You mean the news reports that declared the invasion to be a massive, city-wide hoax after the government covered it up."

Mild irritation pricked at Anne as she recalled that. She understood why the government had covered it up, even if she wasn't sure how they managed to hide something as big as an interdimensional invasion, but it still annoyed her that they had.

"Yeah, those," she mumbled, knowing that Sasha had been just as angry about the coverup as she had been. "Anyway, she reached out to me, and we've been pen-pals ever since; we're actually really good friend. She's actually a full-fledged witch now too." She thought about what she had just said. "Well, I guess she's more of a magical girl rather than a witch since it turns out that witches are an actual species, not just practitioners of magic. She actually found a way to go to and from the Boiling Isles whenever she wants, and now lives and attends college there, but she still visits her mom in the human world regularly." She finished the last of her text. "And, send."

"I was not ready for today," Sasha muttered with a sigh. "Interdimensional beings, witches, the demon realm. Who knew?" She glanced at Anne. "So, what's your witch friend's name?"

"It's Luz," Anne replied. "Luz Noceda. She and Marcy would have been the best of friends. I wish I could have introduced you all."

Sasha raised an eyebrow. "So why didn't you? Even if we don't hang out like we used to, we're still your closest friends. How could you keep something like this a secret from us?"

Anne's face fell, and a deep sigh escaped her. "I wanted to tell you, dude, really, I did. But it wasn't my secret to share. Luz and her friends want to keep the Boiling Isles a secret, so they asked me not to say anything." She threw her arms up in the air. "I mean, hello, can you imagine how people would react if they found out there was an entire world full of demons and witches? We could have a whole interdimensional Salem Witch Trials thing go on. Not to mention all the magic and resources to exploit. The whole Boiling Isles was already almost destroyed by this psychotic witch hunter who turned into a monster. Luz had to temporarily become a borderline god in order to beat him after he merged with the Titan's heart. Not even the Collector could stop him at that point since Titan magic neutralized his."

Sasha was now staring at Anne with a bewildered expression. She had followed along up until she had gotten to the part about the psychotic witch hunter, but had lost her after that. "Um, care to run that last bit by me again?"

Anne sighed. "Never mind. I'll explain later. Right now we need to focus on–" She was cut off as her phone suddenly pinged, indicating that she had a text. "Oh, she responded!"

Her eyes quickly scanned over the text message. Sasha kept glancing at her out of the corner of her eyes, the anticipation practically killing her.

"Well, what did she say!?" she demanded when she could no longer take the suspense.

Anne slowly lowered her phone. "She said we should meet."

Sasha gave her a strange look. "In the demon realm?"

Anne shook her head. "No, at her mom's place in the human realm, that's where the portal to the Boiling Isles is."

That made more sense. "Ok, great. Where's that?"

Looking sheepish, Anne gave her an apologetic look. "Um… in Connecticut."

Sasha slammed on the breaks, nearly causing an accident as the cars behind her began swerving to avoid her vehicle. "Connecticut! That's on the other side of the country! We were worried about Bill getting to Gravity Falls before us before; he'll definitely beat us there if we go all the way to Connecticut first!"

"I know," Anne reluctantly admitted, "but we don't really have a choice. We can't stop Bill without some help."

Looking frustrated, Sasha shouted out her aggravation, dropping her forehead onto the steering wheel and setting off the horn. "Why do we have to go there? Can't she come here? Then we can go straight to Gravity Falls."

Anne looked down at her phone in dismay. "We don't know what we're up against, so we don't know what we'll need from the Boiling Isles to fight Bill. And the only portal there is in Connecticut. We've got no choice; we have to go."

Another frustrated groan escaped Sasha and she lifted her head, putting an end to the beeping horn. "Fine, book us some tickets. I just hope it takes Bill a really long time to find that statue of his."

"Me too," Anne replied as she began looking up flights. "But if he does, then we're really going to need all the magical help we can get."

(A/N: And there we go, the explanation of how Bill managed to return and get into Marcy's head. He was once in the head of a newt who had their mind uploaded to the Core, and a copy of Bill was uploaded with them, then he slipped into Marcy's head when she was hooked up to the Core. I tried to come up with a believable way to bring about Bill's return, and this not only worked out, but also served to connect the two series. And speaking of connections, Anne's story of how she met Luz is what happened in the script reading I mentioned. I provided a little recap on it in case some people decided not to watch the video. Like I said, it wasn't completely necessary to watch since I provided the context, but it's still worth watching to get the full story. And, yeah, Luz reached out to Anne after she returned to the human world, so I made them pen-pals. And now Anne is reaching out to Luz for help in dealing with Bill. Will Luz be able to help her and Sasha stop Bill and save Marcy? You're going to have to stay tuned to find out.)