All three kids are enjoying their time while Bill just sticks around silently. They spend pretty much the entire afternoon having fun despite being locked in. And as the evening starts showing, Samuel is asked to come down by Mrs. Pines.

He comes back a couple of minutes later, explaining to the twins what was just discussed. "Apparently, the snow storm isn't going to calm down until tomorrow, so my parents called and said it'd be better if I spend the night here."

Mabel cheers. "Yay, unexpected sleepover!"

Samuel is bothered. "I don't even have pajamas or anything, though..."

Dipper reassures him. "Eh, don't worry too much, please, it'll be fine." Then, he thinks to himself. "That means..." He gives a quick glance at Bill. "He's gonna stay here too..."

"Something wrong, Bro-bro?" Hearing her sister's concerns, Dipper is quick to do a good job at brushing it off.

"No, of course not! It's good that Sammy is staying safe at our place!". He quickly think "I still can't completely brush away what Bill did, but... I'm pretty sure I can trust him now!"

So, Samuel, invited to do so, really makes himself at home with his friends for the night, until the snow storm stops being so violent. They feast on a delicious hot meal before returning to the bedroom for one last night chat between the three. Bill stays away, looking at the scene in silence.

"Wait, I just thought..." Samuel suddenly speaks up. "Bill..."

He approaches, curious. "Yes, Fuzzball?"

"If I'm not wrong... You could've probably used your powers to end this snowstorm, right?"

Bill casually reveals. "Yeah, I could've done that!" He sees Samuel being surprised, and anticipates what's coming next. "What? I could do anything to alter reality, but apparently it's wrong to do it... Now you're gonna whine because I didn't?"

Sammy tries to calm him down. "No no, of course not... I was just... curious, you know...? I don't blame you for anything."

"Alright, alright, I'll believe that..." Bill says, rolling his eye.

Mabel speaks to her friend about what used to be bad experiences at the time, but now she talks about how amazing Bill's powers are and how he can do nearly everything. Dipper is a little less positive about it, but he can confirm that the triangle is doing a great job at limiting himself.

The entire time, the demon is lost in his thoughts. He used to be a dreaded being to everyone, and now he witnesses how all three kids are perfectly fine with his presence and treating him like a friend, with the bracelet to match.

Then, he's eventually taken away from his thoughts when he heard the kids ready to sleep, with Samuel getting the guest matress and bedsheets. "Good night, Dipper, Mabel..." And then he looks up. "You don't sleep, but good night... Bill..."

Bill looks with surprise and says half-convincingly. "Yeah yeah, sleep well, Fuzzball... Shooting star... Pinetree..."

As he witnesses the three kids sleeping peacefully in his presence, he ponders to himself (but not too loudly). "What happened...? ... Look at me... I used to be the most feared of beings, the most evil, cruel, manipulative... I almost managed to rule this dimension with my own powers and rules..." He leaves a pause, the passion behind his words being reduced. "... Then I was outsmarted by humans and I'm not allowed to be evil anymore, neither can I find enjoyment of it anyway... And..." He takes the time to look at his yellow bracelet. "... Now the kids I've made sure to trick, terrorize and even threaten to get my way... they see me as a..." He used to feel some disgust saying it, but it's mostly covered by his feeling of surprise now. "... friend...? Why...?" He gets even more silent. "... They really want me to change... And maybe I have no choice..."

He gets curious as the unexpected sleepover gives him an opportunity. And as a result of their recent deal, he is able to silently enter Mabel's mind.

He finds the place extremely cheerful, colorful and too overly cute. He figures it isn't too dissimilar to what Mabeland could've looked like as he plotted it, causing him to shudder. "If I could have nightmares, this would definitely be what they're made of..." Bill seems really disgusted. "I better be quick about it...

So he floats around, trying to explore the memory doors of her mindscape. He finds a lot of positive memories that sort of annoy him whenever he sees her being overly excited over something. "... I can't completely blame Pinetree for not always having the best patience with her..."

Still, he finds several cheerful memories of the twins during their life, no matter how recent or old they are. And while he doesn't completely understand that way of heartwarming, he's a little surprised that it doesn't cause him to be that negative. He sees one memory after the other, seeing her trying her best to share her positiveness with her brother.

Hoping to find something else, he continues floating around, seeking for a different area. While he starts going deeper, his advance is stopped by a reckless kid doing skateboarding, wearing a cap backwards and shades, causing him to get angry.

Bill starts yelling. "HEY, watch it..." He takes a good look at the kid in disbelief. "... Pinetree...?"

The kid answers doing his best to sound cool. "What's up, triangle dude? Name's Dippy Fresh!"

Bill is very confused, thinking to himself. "Is this how Shooting star wants to see her brother? It must be, why else would he be in her mind?"

The kid speaks immediately. "Sorry dude, but that place is off-limits! It contains my sweetheart of an older sister's darkest memories and they need to remain buried. So human or triangle thingie, you won't pass!"

The demon frowns, thinking. "Wow, he seems even more annoying than Pinetree himself..."

The kid starts getting even more obnoxious from the lack of spoken answer. "Got it? So move back!"

Bill gets angry. "You got nerve telling me that! I'll do what I want! I'm the master of all mindscapes!" He attempts to pass, but the kid is serious, moving quickly with his skateboard.

"No can do, triangle dude. My dear sis made the rules and I'll help her. It'll be over my body! And by the way, when was the last time you saw yourself in a mirror? Bowtie and top hat are so out of fashion..." The kid says that, taking big pride in his own looks.

Bill gets furious and uses his magic to take the kid's skateboard and violently slam it against the ground, causing it to break in pieces. "HEY, not cool, triangle dude! You broke my board!"

Bill remains angry and yells in his deep voice. "AND NOW I'LL BREAK YOU!" He says that and snaps his fingers, causing the kid's body to outright get dismembered limb after limb before he vanishes, because the demon doesn't have any moral limits in the mindscape. He then yells to himself. "UUGH, what a nuisance...!"

After this incident, the triangle demon continues his advance, finding the doors leading to the darkest memories of Mabel. And he knows what to expect. So as he checks, he eventually finds something familiar...

The day of the sock puppet show. The day he tricked and possessed Dipper... The moment where he was holding her in peril of a very dangerous fall...

"Ooooh, but why would you do such a thing...?" He hears his own voice coming out of Dipper's body, asking that creepily. "Whoops, slippery hands! Give me that journal! You wouldn't want your show ruined, right...?". Posing as Dipper, Bill shows the most sadistic smile possible on that body.

"You didn't seem to have an issue taking the journal from your brother for the sake of your show. Or abandoning him when he needed your help! Don't try to pretend that you're a caring sister, give that journal to me or I end your show! ... Now there's a good girl... After all, who would sacrifice a very important work for the sake of their sibling?" He sees himself giving very scary human faces on Dipper, both when he's angry or being evil. He's silent the entire time he watches that scene.

Bill shuts the door quickly and then eventually finds another dark memory. The day she was horrified at the prospect of losing her brother's physical presence and ran away in tears. He sees himself again... Exploiting the body of a time traveler, lying to her about being able to fix her concerns, exploiting her sadness to get what he wants...

"Give it to me, I'll do what I have to do..." He makes the time traveller's mouth smirk. "Unless you want to leave Gravity Falls forever...?"

And then he sees himself grabbing the rift and breaking it, revealing himself in his loudest evil laugh as he puts the girl in an endless slumber and traps her in a fantasy bubble so she wouldn't be a threat. He hears himself proudly claiming "This bubble is quite possibly my most diabolical idea ever!" He laughs loudly. "Finally, THE PROPHECY IS HAPPENING! THE WORLD IS FINALLY MINE!"

The demon shuts the door violently and looks away, floating in place for a few seconds. "... Why...? Why is she forgiving me...? After THAT?" He yells to himself with a lot of self-loathing as he remembers those events, and he quickly exits the mindscape, watching Mabel sleeping with a smile.

"... Shooting star... ... ... ... Mabel...!" He gently rubs her hair for a bit as he says that. "I... I'm so sorry, Mabel..." His eye is a little squinted by guilt and sadness.

He then looks at and floats to the other side of the room. Dipper sleeps in a fairly calm way. He might not be smiling, but he's definitely having a peaceful rest. So Bill enters his mind.

Dipper's mindscape is a lot more standard compared to his sister's. Much like Samuel, it represents places dear to his heart: his home and the Mystery Shack being located close to each other. At the outside is some kind of plaza with several altars, each one having a statue of the people he cares about. There are also a lot of studies imagery around too.

Bill thinks to himself. "Now this is more like it..." He still shudders a bit at how Mabel's mindscape was. "It almost makes me think of Sixer's with all those books... Not that I'm surprised!"

So the triangle starts to float around to reach the memory doors around the statue of Mabel, and he opens one leading to a distant memory.

The twins are around 5 years old and running around their house happily. They're chasing each other for a game and get really carefree. Then out of nowhere, Dipper accidentally bumps into the table, causing a vase to fall down. They look horrified and the sound of the damage doesn't go unnoticed.

Mrs. Pines enters the living room and sees the damage. She asks "Which one of you did this?", ready to give a rightful punishment.

"Um..." Dipper starts to make a sound, but before he can.

"It was me, Mom! I'm sorry..." Mabel looks away while her brother is shocked.

Mrs. Pines takes a knee and tries to be reassuring while doing what she has to do. "I appreciate your honesty, Mabel, but I'm gonna have to punish you from desserts for two days."

Mabel starts tearing up, but she leaves out a calm "... I understand..." before leaving to her room. Her brother is quick to join her.

"Sis, why did you lie...?"

Mabel is crying, but isn't angry about anything. "I... I got scared for you, I guess, Bro-bro... I didn't want you to get punished. So..."

"But this doesn't feel right... I mean, I thank you, it's sweet of you, but..." He goes to comfort her and show his gratitude. He's really not sure what else to say.

By extreme irony, it happens that the dinner has chocolate brownies, one of her favorites. But she accepts her punishment without a peep and goes to bed in silence.

Then when her brother joins her... "Psst, Sis..."

Mabel keeps looking at the wall in a curled position. "What is it, Mason...?"

"Just turn around, please." He says, and as she does so, she sees him holding half a brownie.

"Wait, what...?" She doesn't get why he shows her.

"I felt bad for you taking the punishment for me, so I thought I'd let you have some of my share of dessert. I hope that's enough to repay you."

Mabel gets a smile back and hugs him, which definitely answers his worry. He gets a smile himself as he sees her happily eating what he brought her. "Thank you so much... You really are the best brother!"

The boy's stomach growls a bit, he could have used some more dessert. But he ignores it when he sees his sister's smile, and smiles as well.

Bill closes the door, thinking to himself. "Pinetree was always the kind to sacrifice stuff for his sister... But Shooting star seems to have a sacrificial side to her as well... Maybe she deserves more credit than what I gave her back then." Just saying that makes him think of the puppet show again, bringing back bad feelings. "Ugh... let's see what else I can find..."

Bill approaches one of the memory doors around the Samuel statue of Dipper's mindscape. So he opens and witnesses a memory from when Dipper was 4 years old. At this point, he and Samuel barely started to become friends.

The two boys are running after each other in the grass while Mabel stayed behind with the parents since she wasn't done yet with her snack time.
Samuel runs away from his friend, giggling. "You won't catch me!"

But Mason, or as he now tries to adopt the new nickname, "Dipper", is just as playful. "We'll see about that!"

The running on the grass leads them under a tree, and unexpectedly, Samuel trips on a bumpy root.

"AH!" The kid loses his balance and falls down a grass slope painfully.

Dipper reaches the top of the slope and is horrified. "Are you okay?" His friend doesn't answer. "Oh, no no no no no..." He carefully goes down the slope to join him and repeats the question.

All he gets for answers is Samuel sobbing from the pain as he touches his left ankle. Dipper looks concerned... "Are you hurt...?"

Samuel just raises his head to look at his friend, trying his best not to cry, and nods in silence.

"Can you stand up...?" His friend tries, but the pain is too big.

"I can't do it... I can't move..." Samuel answers desperately.

Hearing this, Dipper starts to frown, talking confidently to his friend. "Of course you can! I'm here to help you, it won't be a problem, I'm sure! Grab my hand..." And so Dipper tries his best to have Samuel's right hand on his shoulder so he could try to stand on his left leg. And he looks at the slope. "It might feel a little difficult now, but step by step, we'll get there!"

Before starting to move, holding his friend close to help him, Dipper looks at him and uses his eyes to gesture at his skull. "You were here to cheer me up... I wanna do the same..." Being reminded and hearing that allows Samuel to cheer up just a little bit.

And just like that, Samuel is doing the best he can to climb up with Dipper's physical and emotional support. The climb is kind of painful and it takes some breaks, but they ultimately succeed.

As they reach the parents and explain what happened, it's thankfully observed that Samuel's wound isn't severe and that the pain would go away in a matter of days.
Samuel hugs his new best friend for helping him, even if he doesn't need thanks.

"Hey, Samuel... I'm thankful for you helping me feeling more confident about my birthmark, and I'm slightly taking a liking to the nickname, but... I feel like I still wanna make sure people can't see it. So I thought about asking for a beanie or some other hat as my next gift. Is that... okay with you...?"

Samuel frowns a little bit, he feels like his friend is still growing insecure despite his encouragements. "I would mind a little, but..." He says things as they come. "I guess I understand what you mean by that, so... yes, I think that'll be okay! As long as you aren't in discomfort with me or your sister, because you deserve to not mind it all the time!"

"Dipper" smiles. "Thank you, Sammy, I appreciate it!"

Bill closes the memory door and thinks... "So much wholesomeness in these three kids memories... And so much kindness... Is this how joy feel...? I mean, non-evil joy...? Could I be able to feel it...? Someday...?"

Bill once again explores... The less bright parts of the boy's psyche. And he finds memory doors that look a lot more sinister. And even without breathing, Bill makes a sighing sound, knowing what to expect there.

So he opens the darkest door of the lot and recognizes the Fearamid, causing him to actually feel something close to disgust. "Oh no..."

Dipper and Mabel are running horrified as a giant monstrous Bill runs after them. "When I get my hands on you two, it'll be a great pleasure to DEASSEMBLE YOUR MOLECULES!". And then he sees the moment where he uses a tight grip on them. "Hello, you guys...!" He hears himself in the memory yelling... "You lost, Fordsy! I got your precious kids! And I think I'll kill one of them just so I can have some fun!" And as he hears himself starting the playful countdown and roulette, the door closes violently, causing Bill to panic and exit the mindscape, looking at Dipper, who's sleeping peacefully.

Bill looks at him snoring and he whispers, with a lot of pain and sorrow in his tone. "... I know you won't ever be able to completely forgive me after that, Pinetr... ... Dipper... And... I understand why..."

After that, he just silently reaches for Samuel's mattress, and... "... I don't deserve this..." He removes the friendship bracelet and disappears for the rest of the night.

Once morning rises, it is possible for the kids to see that the snow storm has calmed down. But while Dipper and Mabel are looking outside, Sammy feels confused as he finds Bill's bracelet left behind.

"Looks like you'll be able to go home, Sammy!" Mabel says cheerfully until she turns around and notices her friend looking confused. "Uh, is that Bill's bracelet? What is it doing here without him?"

Dipper turns around surprised when he hears that, then deduces "Bill can't go too far away from you, I'm sure he's around somewhere... And he can hear us... Maybe he's feeling intimidated for some reason..."

Samuel thinks and talks to his friends. "I'm sorry to ask this of you two, but could you please leave me alone in the bedroom? Maybe Bill will feel more comfortable with just me for now..."

Mabel sees no problem. "Okay, I wanted to prepare breakfast for us anyway!"

Dipper follows her outside, but he's not sure what to think of Bill right now. A part of him wonders if getting rid of the bracelet is a way for him to return to his old evil ways. Because of that, he remains upstairs by pretending to his sister that he has to use the bathroom first, waiting to see if he has the chance to get a peek at the conversation between the two.

Sammy sees Bill showing up, both are unaware that Dipper is listening.

The kid feels no anger, just confusion and some worries. "Why, Bill...?"

The demon answers without his usual confident loud tone, as he tells the truth. "That night, I explored your friends' mindscapes while they were sleeping..." He notices the concerned stare on Sammy's face, causing him to add. "No, I didn't do anything bad!"

Dipper has a silent gasp as he hears that, but he's willing to hear the rest of the explanation.

"And doing so, I saw some of the horrible things I've done to them during their vacation... I relived them as a spectator, and... I was truly the most awful person alive... I really don't think I deserve to be forgiven by them... So, I'm unworthy of what you consider friendship, that's why I removed it..."

Samuel wants to be reassuring. "You're wrong, Bill... They are forgiving you... They want you to feel better. They can't lie about this..."

"But I don't deserve it... What I've done is beyond redemption... I'm not too surprised Shooting star would be quick to forgive me, even if..." He stops for a couple seconds as what he's done to her flashes back, "but Pinetree... I don't see him ever forgiving me... I'm the worst! And he's right to still hate me!"

A voice surprises the two of them. "I don't hate you..." Dipper opened the door, looking conflicted.

Bill freaks out as he realizes that he heard everything "PINETREE?"

Dipper steps in and speaks directly to Bill before anything else can be said. "Look, I can't disagree with the fact that I struggled to believe you could change since that time you hijacked Sammy's body for revenge... But as Mabel told you a couple of times... the past is past... And you can continue to change for the better... I mean, I wouldn't have ever believed that Gideon could be anything else than a greedy, possessive, manipulative brat. Or that Pacifica would be anything else than an arrogant girl because her family got wealth. But both have proven me wrong... And... you can prove me wrong too, I know it!"

Bill stays silent and Dipper takes the bracelet from Samuel's hands. "So please... Put it on, my friend..."

Bill is shocked to hear that from him. "Why do you want that? Don't you have hesitations, Pinetree...?"

Dipper gives him the yellow bracelet back and grabs his hand with a very genuine smile. "Bill, please... I trust you completely! And I give you a deal... From now on, you can call me... your friend! Now, and always!"

Bill reaches for a friendship cuddle. The morning light in the room gets brighter as the hug happens, while Mabel arrives confused with the breakfast platter. She simply asks Samuel in a whisper. "Did I miss something...?"

Samuel answers in a whisper too. "Yeah, maybe, but don't worry..."

With that, the breakfast between the three takes place, and Bill shows no issue sticking around and contributing to the conversation when he wants to. All four of them have a good time before Samuel leaves for home, he once again thanks every resident of the house for their sudden hospitality from the snowstorm and goes home, thinking about how great the moment was.

Author notes: And, here's a long time coming! While what I consider Act 2 has yet to end, this is a huge turning point of the story that will remove most if not all of the negative/conflicted feelings between the main characters.

Which hopefully is good enough timing. Dipper taking time to trust Bill completely is understandable. Maybe I dragged this a little too long, maybe not.

Thanks for reading, I hope you had a good time doing so!