A rough night for the two twins passes. Mabel woke up quickly and left the bedroom without a sound to get ready for a day, since she does not want to speak to her brother again, per his request. Dipper wakes up grumpy and puts up a lie to his parents about joining school. So he leaves home and, with a giant sigh, he just stands alone on the nearest park during the school hours, looking angry and feeling defeated for hours.
In Samuel's class, Bill feels incredibly bored without having his precious "pal" around... It was a long boring day of him just thinking about other things to do to have his fun. And during the breaks, he notices that Mabel doesn't ask Samuel anything about Dipper's whereabouts, making it clear to him that it went wrong between the two.
The last class of the day is art class, and finding this out gives him a glorious idea. Using his knowledge, he manages to steal something from the chemistry classroom to put it on one of the paint buckets. It'd be a long process, but he knows it'd be worth it and knows it'll happen near the end of the school hours.
After what felt like an agonizing wait during the class... The chemicals work, causing a big explosion, and the content of the bucket of red paint splatters all across the art room and on the students, including Samuel himself. He chose a fairly interesting color for the imagery too, and Bill laughs hard internally and he hears the panic and disgust around him.
The teacher has good reasons to be unhappy. "Who did this? Somebody better confess!" Obviously, Bill doesn't. "If everyone stays silent, then I have no choice but to give detention to the entire class on Saturday!"
The whole class make sounds of complaining, pain and disappointment, while Bill lets out a gigantic "YES!" inside.
But then, suddenly... "I bet it was Mason!". The statement causes Bill to go "Wait, what...?"
Other voices from the classroom get heard. "That boy acted like such a weirdo, that's likely". "He acted like a freak, he could definitely do something like that". Bill gets confused.
He then hears "We need to have him confirm he's guilty!", which causes Samuel to stand up.
"Alright, everyone! I'll do it! As his best friend, I'll go meet him and get him to confess in front of everyone!" He says that with a lot of conviction as the end of the school day rings.
Bill leaves the school with a determined look on Samuel's face as he makes his way to the Pines residence. On the inside, he keeps telling himself. "I'll get Pinetree, and I'll make him the scapegoat to the entire class! Who cares, his school reputation is already ruined anyway!"
And so he reaches his destination, but it takes him some time to think. On the inside, Dipper got home without telling anyone where he was, locking himself in his room, and Mabel is minding her own business in the living room with Waddles. After a lot of thoughts on how to proceed, he finally pushes the doorbell.
Mabel opens the door. "Oh, hey Sammy!" She acts fairly cheerful to him. "What are you doing here? You didn't tell me about a visit."
Samuel goes straight to the point. "Hey, sorry to intrude, but I need to see your brother!"
Mabel groans a bit, being reminded of what's going on with him. "Why is that?"
He doesn't answer directly. "It's complicated..."
She gets a little curious about that. He usually doesn't keep secrets from her. "What do you mean? You can tell me...". And then she notices something. "Wait, what's that on your shirt?"
He avoids answering the question in details. "Nothing big, just some paint..."
She gets more and more serious in her concerns. "What happened? Have you done something?"
Bill actually gets nervous, thinking: "Darn, she's on to me...". So he answers. "No, why?"
She puts her face closer to Samuel's in suspicion, which makes Bill think "Oh no...". He closes his eyes to prevent her from noticing the possession, which only does make him look more untrustworthy.
The girl stares at him pretty close with her eyes squinted while she tries to figure things out. "Are you... hiding something from me...?"
He actually gets a bit nervous, feeling some pressure. A very rare occurance for the overconfident demon. He avoids answering again. "Tell me where your brother is! After I meet him, I'll explain it to you."
She gets stern. "No! Tell me! There's something you're not telling me! You're hiding something!"
Samuel answers with a question. "What could possibly make you think something so silly, Shooti...?" It was at this split second, this exact moment, that Bill wanted to bite the human tongue he uses, because it did a fatal slip here. Mabel gasps and takes a step back, raising her eyebrows and she looks shocked.
She speaks in disbelief, wanting her hearing to have been wrong. "... Are...? What did you...? What were you... going to call me...?"
Samuel groans and sighs in resignation. He starts speaking loudly again. "I guess you got me fooled, Shooting star...!" He slowly opens his eyes to confirm, as Mabel shakes in horror at what she's seeing... "I am Bill! Bill Cipher!"
"Y-you're back..." She gets scared and wants to find a defensive item in the room. "What have you done to Sammy...?"
He acts cold, but not threatening. "I told you what you wanted to know, now where's your brother?"
The girl has no choice but to be true to her word. She does so with a huge distrust. "He's locked in his room. Good luck getting him to talk! He's been avoiding dialogue with everyone since yesterday!"
"Good, then. I'll pay him a little visit..." He walks up the stairs, keeping his straight face and knocks at the door. He gets no answer. So he tries again with no better results.
He thinks to himself. "Guess I have to do it the hard way..." He takes some momentum and runs against the door, hurting himself in the process. "Pain is fun, so I can do that all day if he wants to be stubborn!"
He does that a second time, even harder than the first. And this does get a reaction as Dipper start unlocking the door, annoyed, without looking. "Mabel, are you seriously about to get your shoulder broken just so you can...?" He then notices who did this, and he is livid. "YOU?"
Samuel stands up, staring at Dipper and his angry face with his yellow eyes, with a fairly cold stare. After a few seconds of silence, Dipper starts ranting. "You got a lot of nerve, following me to my home after what you did. First you ruin my summer, then you make my best friend disappear, then you get my reputation ruined. What more do you want to do to ruin my life, you absolute psycho?" He starts clenching his fists "Get out of here before I..." Bill gets him to shut up out of nowhere, by... suddenly making Samuel give him a hug. A warm, heartfelt hug...
Author notes: Well, I don't really have too much to say on that one, except, there's the beginning of the Mabel focus I promised.
And um, sorry about the cliffhanger, I suppose, but that's a storytelling trademark, so I had to to some degree.