A knock on the door, and I slammed the laptop shut, my heart ramming into my ribcage.

In the summer that I was fifteen, I was starting to watch a lot more pornography.

There were troves of it, just sitting there, on the internet, for free, and I could find something new and load a full twenty-minute video in a matter of seconds. Even if I exclusively watched porn, video after video without breaks, right up until I was lowered into the grave, I estimated that I wouldn't get through a tenth of what was out there.

That day, my voyage across the ocean of X-rated websites had landed me in a lesbian category. It was something that I had often seen down the side of the page, constantly offering itself to whoever might be interested, but I had never clicked any of the blurry thumbnails, until that day, when curiosity must have gotten the better of me.

I found it kinda gross. I was fine with the kissing, and the nudity, because I'd seen it all on-screen before, but when they started to get down to business I decided that it just didn't make sense - they were trying to have sex without either of them possessing one of the two things that make sex work. They were using their hands, but that meant their fingers got all sticky, and yet they still found it necessary to rub them all over one another's skin and hair, spreading goo to every nook of their bodies. The redhead was just about to set her tongue to work on the blonde's nether region - which was all kinds of weird - when I was interrupted.

There was another knock on the door, and my mom called my name through the wood. I realized I had been sat cross-legged with my pants pulled down and the image of two girls going at it burned into my eyeballs.

"Yeah - coming," I shouted, jumping out of bed and frantically tugging my sweatpants back up. I opened my bedroom door and Mom had disappeared, so I jogged down the stairs and found her watching TV in the living room. "What?" I asked her.

"Somebody was asking for you at the door."

"Okay," I said, pointedly scanning the hallway. "Where are they?"

She blinked at me, like I was braindead. "At the door."

"You didn't let them in?"

Again with the slow, deliberate blink. Before you start worrying that my mom was mentally ill, or anything, don't. She was just very much obsessed with herself, and held herself above the kind of social norms that you might expect and appreciate from a regular human being. I rolled my eyes and traipsed to the front door.

The first thing I saw was a flip-flops and jeans combo, so my visitor had bad fashion sense, then I saw a baggy blue and pink sweater, so they obviously had terrible fashion sense, but then I noticed that it was Mabel Pines, and I dropped the charges, because generally, Mabel Pines was pretty fantastic. My jaw dropped open.

"Surprise!" she squealed, throwing her arms out to the side.

"What?! What are you doing here?" I exclaimed, stepping out onto the concrete porch and wrapping her up in a hug. "I didn't think you were getting here until next weekend."

"Yeah, well, I lied to you. Just so I could see the look on your face," she said, prodding me on the nose and waltzing past, into the house.

We didn't have much to catch up on, because we had texted each other daily since the last summer's end, but we still sat on my bed and talked for hours. It was surreal at first, like I had never expected her to come back, but there she was anyway, her braces gleaming in the sunbeams and her laugh bouncing off my walls.

"I can't believe you're here," I kept telling her, and the warm feeling bubbling inside of me wanted to say more, but I felt that it would be out of character, so I didn't.

Things carried on like that for the rest of June. We were thick as thieves, spending our days exploring the forest around her uncle's tourist trap, spending our evenings in the attic or in my bedroom, playing the piano, watching romcoms, going on those chat-roulette sites and plowing through thousands of penises just to find another couple of youngsters to talk to, sometimes on the other side of the globe.

Mabel wasn't like any other teenager I knew in Gravity Falls. She woke up early on summer days, for a start, and when she stepped outside and inhaled the morning air she didn't think about hitting the mall, or heading to the local park to smoke cigarettes on a picnic bench and scare away children, or turn around and go back to bed. She just strolled into the woods and let adventure come to her.

I wasn't so into it, all that nature and shit, but she had a manner of making it fun, and I couldn't even tell you what that was. I think it was just her. She had a positive reaction to everything that happened, everything that she saw, no matter how trivial, like a squirrel dropping acorns from the trees or a wooden fort that some kids had abandoned half-built, and it was infectious. I'd roll my eyes and tell her how dumb she was and complain about the mud on my boots, but every time she looked away I'd smile or laugh under my breath.

Each day we ventured farther into the forest, until eventually we came to the edge of the lake and found an old fishing platform, adjoining what might have once been a parking lot, but was now overgrown with ferns. Mabel walked right out onto the platform, despite the wooden planks looking aged and rotted at the sides, and I stood back on the dirt, half of me wanting to reach out and pull her back, but half of me cracking up at the thought of her falling into the water fully-clothed.

She reached the end, jumped a few times, her sneakers pounding the wood and echoing out across the otherwise still lake. I flinched.

"It's fine," she called out. "Quit being such a baby," and I wasn't a baby, but I did succumb to peer pressure exceptionally easily.

I walked up next to her, gazed out across the water. Way out in the distance to my left was an uninhabited island that I'd never set foot on, and about the same distance to my right was the beach that the boats docked at and the townspeople fished from. Out here, we stood in silence, save for the birds chirping and the ripples of the lake, and our breathing. We declared the dock 'our spot,' we weren't ever to bring anybody else here. And I was more than fine with that.

But July fourth came around, and we went down to the fireworks stand that was set up in the parking lot of the convenience store every year, and we convinced Mabel's uncle to shell out for a spectacular display in their back yard, but all the while, Mabel was getting all buddy-buddy with this boy she had made friends with, who I didn't know about until a minute before he showed up at her uncle's house.

Andrew, was his name. He had Harry-Potter glasses and neat, gelled, dark brown hair, and I had to stare at the back of his head as we walked to the convenience store, his arm linked with Mabel's. They kept whispering things to one another. She kept nudging him with her elbow. He kept making her laugh. We had Wendy Corduroy and her boyfriend-of-the-month along with us too, and they were hanging back, probably pretending they weren't chilling out with an old man and a bunch of high school freshmen, so I was left to talk to Dipper.

It's not that I didn't like Dipper. He was cool, and nice to me, and I had longovercome my crush on him from the summer before. It's just that, with Mabel repeatedly throwing her head back in laughter, making her pigtails bob up and down, while I couldn't hear a word of the comedy genius that Andrew must have spouting, it was hard to concentrate on Dipper's anecdotes.

Sorry, Dipper. Some girls just don't care about alien spaceships, no matter how many of them you claim to have seen.

We hauled a few backpacks full of fireworks back to the Mystery Shack - Stan Pines' house-slash-gift-shop - and sat around out the front eating barely-cooked hot dogs off of the barbecue, soaking up the last of the sun before it was due to rain for a week straight. It disappeared behind the treeline, then the horizon, and then we were into those hours of the day where my tank top and denim skirt weren't defending me from the wind, so Mabel ran into the house and brought me one of her hoodies. I didn't even have to ask. But then she went back to the tree stump that Andrew was sitting on, and I wanted to fire up the barbecue again and burn the shit out of that hoodie, just for attention.

I told myself to calm down, stop being so insanely possessive, and actually try to get to know the guy. Maybe he would turn out to have a hideous personality and I could warn Mabel away from him.

But he was really, really, really sweet. I perched on the stump next to him while Mabel ran around with her brother organizing the fireworks, and he told me how he lived with his grandparents because his parents died when he was young. He told me that his grandma was in the early stages of dementia and that he was going to learn to drive as soon as he turned fifteen so he could take her to her doctors' appointments, instead of his grandpa, whose body was less able than it used to be. He was due to start his freshman year at the same school as me in September, and he was really glad to have found Mabel because none of his friends were around for the summer.

I wasn't as pleasant a human being as Andrew was, I decided later that night, because I hatched a little scheme to get back at Mabel for all the jealousy she had indirectly caused me throughout the afternoon. Wendy and her boyfriend, Klaus - German, I think - were getting touchy-feely on the old couch on the porch, and sitting right next to Dipper, I could tell how uncomfortable he was, his eyes flicking to and from the pair like a metronome on steroids. I saw an opportunity to kill two birds with one stone, I suppose, although I'm not sure either of those birds needed to be killed in the first place.

"You've really got a thing for her, haven't you?" I said.

Dipper looked at me, his cheeks flushed under the light from the porch, and sat up straight in the plastic chair. "No."

I raised one eyebrow, tapped my foot restlessly against the dirt.

"Okay, yes," he said. "But don't tell her."

"I won't," I said, and I wouldn't. I wasn't a monster. Well, I wasn't a monster when it came to doing things that I didn't personally gain anything from. "You wanna make out?"

"What?"

"With me. Do you want to make out with me? It would make it easy as shit to find out if Wendy likes you back."

He thought about it for a moment, and then, right there, on our crappy little plastic chairs, he leaned in.

I slapped his knee. "Not now. After the fireworks."

"Oh," he said, and pulled the bill of his cap lower.

The sky faded to black, and the stars came out. While Stan used one of those long grill lighters to light the first fuse, I watched Mabel, standing further back than the rest of us, her hands held up to her chest and tucked into the sleeves of her sweater, eyeing the box on the ground with distrust. I was half-hoping she would come over and stand next to me, and over the explosions whisper wishes in my ear, but I wasn't sure she even remembered last year on the balcony.

There was a whistle, and everyone flinched slightly, but I didn't take my eyes off of Mabel and her new best friend until the third explosion. I watched their eyes shoot upwards, and their faces turn green, and then purple.

We used the best of the fireworks first, it seemed, so the very last box sputtered out pitiful sparks that barely made it above our shins. It may as well have sprung out a giant middle finger and laughed at us. While everyone began to applaud, and laugh, and discuss what to do differently next year, I dragged Dipper by the hand around the side of the Mystery Shack, where we were still barely visible and the conversation became a low hum to our ears. He didn't say anything, because he knew what I was doing, but I felt the need to remind him quietly that this wouldn't mean anything, and he nodded. I plucked the cap from his head and gasped into his mouth because he didn't waste any time.

We made out with my back pressed against the hard exterior of the Shack for a few minutes, and I'm not sure who ended it. We both pulled away for air at the same time, and everyone would have seen us by now, so we stopped, but for a split second, I contemplated pulling him back for round two. He was good, more so than any of the boys I had dated from school, more so than anyone would have thought just by looking at his nerdy outer shell. And maybe Wendy would eventually wise up, because he sure smelled a lot nicer than Klaus.

Dipper smiled down at me, tapped the wood above my head a couple of times, for no discernible reason, perhaps to signal that the moment was over, perhaps to kill the silence. Then he walked back to the group, and I lingered against the wall, a forest of shadows opening up before me without his body to block the view.

Maybe in another life we could have been something. But no matter how good he was at kissing, there was something wrong. Something missing. And in the black canvas of the forest, the blonde and the redhead from that one video crawled into my mind, played with one another in front of me, tugged at each other's lips with their teeth. My eyes widened on their own accord, then squeezed shut. I shook my head violently and hurried back to the front porch.

It didn't rain after all, because weather forecasts in my hometown have always been beyond inaccurate. My dad always said it was because the local news station's weatherman was of Pakistani descent, and he stood no chance of predicting the weather if he "can't even speak English properly." My mom always slapped his arm with a magazine when he said that, which was about the proudest I ever felt of her.

The day after our lackluster fireworks display, Mabel and I found our way back to the fishing dock - our spot - kicking pinecones and laughing at each other's embarrassing childhood memories, the kind of stories that were too long to tell over text messages. We each slumped against opposite wooden posts jutting out of the water, my left leg straightened out parallel to her right, our bare knees touching.

The tranquility of the place consumed our conversation, and a few minutes later, hypnotized by the sun dancing on the surface of the water, Mabel's voice startled me a little.

"So what's going on with you and my brother?" she asked, and when I turned to look at her she raised her eyebrows with her mouth in a straight line. I wasn't sure if this was going to be a friendly inquisition or a waterboarding.

"Nothing," I told her. "He asked me to kiss him to make Wendy jealous."

She frowned, tilted her head, which was her response to so many things that I didn't know how to interpret it anymore.

"And I like kissing people, so I said yeah, why not?"

"Alright," she shrugged. "Did it work?"

"I dunno. Don't really care. What we should be talking about is where did this Andrew come from and why were you all over him yesterday?"

She hummed and leaned her head back against the post. "Isn't he great? He's so sweet. I met him at the pool last week and we were like, bam, insta-friends. He's starting at your school this year, you know."

"Are you... into him?"

"Andrew? He's gay," she said, chuckling, as if that was supposed to be obvious and I was dumb for not knowing.

I went into robot-on-standby mode while I re-evaluated everything I had witnessed the day before, all the touching, and the giggling, and felt all the frustration I had tucked away slowly fizzle out.

"You... do know what gay means, right?"

"Yes, I know what gay means," I snapped.

"And you're cool with that, right?" she asked me with her eyebrows drawn together and her head lowered, like she was the fucking ambassador of the gay community and I would be hanged on the end of this very dock if I didn't jump up and start waving a rainbow flag around.

"Of course I'm cool with it," and I was, I think, because I imagined Andrew kissing another dude and it didn't freak me out.

"I'm gonna make it my summer mission to find him a cute boyfriend," she said.

I hesitated, then like a mopey six-year-old said, "I guess that means you'll be spending a lot of time with him," at which point the ball seemed to drop for Mabel.

"Is that what you're worried about?" she laughed, rising to her feet, and just as I thought she was going to walk away without me, she cuddled up against my post and lay her head on my shoulder. "Andrew can't hold a candle to you."

I gazed down into her silky hair, picked a leaf fragment out of it instinctively. "I know that," I said, a smug grin devouring my face, but as I sat there and thought about it, about Andrew taking care of his grandparents and donating his allowance to orphanages, there wasn't anything I could think of for him to hold up his candle to.

The summer flew by, as summers often do. I spent so much time outdoors that whenever I returned to my room at the end of the day I felt all claustrophobic, several times a night going out to the balcony and breathing in the air, staring out across the pines, looking up at the stars when the sky was clear and memorizing the few constellations I could see. I also, predictably, spent so much time with Mabel that those nights came hand-in-hand with anxiety, because soon she would be shipped back down to California and my old, habitual life would resume, and I knew I would get used to it again, I had to, but god, I wished she could have stuck around just a while longer, just until Christmas, or until next summer, or until I died.

I got to know Andrew a little better, we both did, but he didn't like leaving his grandparents at home alone for hours at a time, so he wasn't always around.

The last thing about that summer that stuck in my head was towards the end, one of the final days in August. The temperature was dropping, giving way to autumn, but Mabel in a sweater, me in my purple fleece, we were fine. After dark, we grabbed a couple of sleeping bags and pillows from the seemingly all-encompassing supply closet in the Mystery Shack, a flashlight from the attic, a jumbo bag of chips from the kitchen, four cans of Diet Coke, and we walked close together through the woods, Mabel waving the flashlight around all Blair-Witch-Project-like.

At the fishing dock, we rolled out the sleeping bags side-by-side. It made me a little anxious that our pillows touched the edge of the dock, but unless I managed to accidentally spring into a backflip from lying down, I wasn't going to fall in the water. Mabel hung the flashlights from one of the posts, but couldn't really control the direction of the light, so we lay on the dock, all wrapped up with our arms touching through the thick lining of the sleeping bags, and our feet brightly illuminated. Every time we turned our heads to look at one another, the light hit her chin and cast sinister shadows over her face, and fully aware of this, she kept laughing in a deep voice and threatening to throw me into the lake, which I hated.

I always felt like I drifted in and out of consciousness during our conversations, so sometimes we would end up talking about something and I wouldn't remember how we got there. Over the sound of crickets, nesting in the reeds surrounding the lake, Mabel was telling me about the three different boyfriends she had allured over the last year, which I had heard all about before, but not in this much detail. She was rambling, hyped up on caffeine.

I found it kind of uncomfortable, which was strange. It wasn't because I had only dated two boys myself - there was initially a tiny bit of jealousy, and questioning what I was doing wrong, but I was over it. And I had thought that I only didn't like seeing her with Andrew because it meant she was spending time without me, focusing her attention on somebody that wasn't me. Me, me, me.

But listening to how Chance could tie a knot in a cherry stem with his tongue, how Billy was a star running back and he was only in sophomore year, it all really bothered me. From the descriptions she gave me, I was picturing those boys in my head, cuddling up to Mabel, kissing Mabel, and I wanted to reach into my imagination and ram my fist down their throats. Which didn't seem like a healthy thing to be thinking. I was very protective of her, I supposed.

I woke up to a clear sky, to birds chirping, to the water lapping at the dock's supports, and I sat up, saw the brunette sleeping silently beside me, her breath tickling my hand.

At first I thought it was still evening, the sky indigo and the air chilly, but that couldn't have been right, because we were stargazing only moments ago. I leaned forward, not willing to emerge from my warm cocoon just yet, and grabbed the backpack at the foot of our makeshift bed. I rummaged around for my phone, and it struck my eyes, full brightness, but I squinted and read that it was 5:30 A.M. I looked around again, like I somehow knew better than the clock, because it definitely looked like twilight outside, but then I had this crazy revelation that it also probably looked like that in the early hours of the morning, I was just never awake to witness it.

"Mabel," I croaked, and then cleared my throat a couple of times because I sounded on the brink of death and it wasn't the least bit attractive. "Mabel," I repeated, shaking her arm.

She woke with a start, sprang upright, and our heads almost clashed. She looked around, at the woods, the lake, our sleeping bags, her mind ticking through the same thought pattern as mine had. "What time is it?"

"Five-thirty."

"Oh shoot, we've been out here all night? Dude."

Her phone had thirty-seven missed calls and sixteen messages from five different people. It made me frown and check my own, but I had nothing. I even unlocked it and went into the Messages app, just in case they hadn't popped up on my home screen. I turned it off and switched it back on again. Nada.

Mabel got onto the phone with her uncle, who picked up right away. I wasn't paying much attention, but he sounded more relieved than pissed off, and then she called Dipper, who was also awake, and I couldn't hear him very well because he speaks so quietly into the receiver, like everything he's saying is top secret and he's not even sure he should be declaring it out loud. Then she fired off a few texts. I lay back on my pillow and studied the sky, anger consuming me. The sleeping bag felt more like a furnace now, burning me alive.

I was aware of Mabel rummaging around in her own bed and standing up, and then a loud splash split the silence, and I turned my head to glance across the dock, and she was gone. Forever paranoid, my first thought was that she had fallen in and was now drowning, but as I rushed to the end of the dock my foot got tangled up in her t-shirt, and her face came into view, and I saw that she was not drowning, she had just gone totally fucking nuts and decided that stripping down to her bra and underpants and jumping into a lake before the sun had come up was a fine thing to do.

She bobbed in the water, grinning up at me.

"The hell are you doing?" I asked her, folding my arms across my chest because just the thought of being in there made me shiver.

"Haven't you always wanted to wake up and go for a swim, before you do anything else?"

I glanced across the lake, at the cliffs and the forest on the other side, I guess to check if anybody was watching. "No?"

"Well, it feels great. They have these hotel rooms now where the bed is in the middle of a swimming pool, so you have to take a dip every time you get up. It looks incredible."

"That sounds... horribly impractical."

Mabel inched forward and folded her arms over the edge of the wood, splashing my bare toes. For a moment she just looked at me, that smile plastered to her face, the sign of her inner deviant working away, plotting her next moves. She held out her hand, palm to the sky.

"I'm not getting in there," I told her.

"Yeah, you are."

"No, I'm really not."

"Pacifica, I can't see into the future, but if I could, I would see you stepping into this lake, on this beautiful morning."

I crouched down and dipped my toe in. It actually wasn't too bad, if you completely changed your definition of not-too-bad. It was fucking freezing.

But then Mabel added, "one of the few mornings we have left," and I thought screw it, I would be as compulsive as she was for once.

I folded my clothes in a neat pile and left them on the sleeping bags, because I wasn't going to scatter them about the dock and get them all dirty like some kind of animal. My feet tingled as I sat on the lip, my legs dangling into the water, and I kept withdrawing them until Mabel convinced me to just jump in without thinking about it.

So I did, and once my head was above the surface again, I started cursing profusely and blinking water out of my eyes. At first, the water felt like a block of ice, but I flapped my arms around like a toddler without armbands and that warmed me up. Mabel bet me that she could beat me to a rock further along the shore.

"I doubt that," I told her.

"People say I have mermaid blood."

"I have no idea what that's supposed to mean, but people say I was the school's champion of the 500 meter freestyle two years running. Because I was."

"Yeah," she said, paddling closer, right up to my face. She tilted her head and clucked her tongue. "But people say you're also full of shit."

My mouth dropped open. "Oh, you are so on."

We stayed in the lake for about an hour, until the sky turned blue. I walked back to the Mystery Shack with Mabel, and stayed there until that evening, when my mom finally called to ask where I had gotten to, with only the tiniest hint of concern. Mabel kept me occupied the whole time, never letting quiet drape over us, and I think she knew what was wrong, I think she had seen my phone earlier on the dock and that was why she started distracting me. Helping me with my problems without declaring them out loud, which I genuinely appreciated, more so than I would ever vocalize.

It was some time in the afternoon, when we were sat on her bed, filling out one of those online personality quizzes, that I decided that she knew me better than anybody, because I tended not to let people know me at all. She knew my hopes and fears and strengths and weaknesses, all of me, the real me, the girl behind the designer sunglasses and the paragon of make-up. And she didn't judge the real me, or put me down, or poke fun - all of the things that intimidated me about opening up to the world.

I had never had a friend like that, and it made it that much harder to say goodbye once September rolled around.