You curse yourself mentally. Speaking nonsense out loud in public is definitely not the smartest idea. Luckily there was no one around to notice.

With one last glance at the house, you start your march towards the king's castle. You feel shaky both from excitement and nervousness. There's no clear plan for what you should say or do when you reach your destination but you don't think anyone can really plan out something like this. And after all, moving forward beats sitting and doing nothing.

'don't forget that you can just think loud enough and i'll hear that,' Sans gives you a little reminder. 'i would actually prefer that.'

"Hm? Why?" you ask curiously.

'well. it's a little bit disturbing to talk to someone who has my voice, y'know? 'sides, your voice sounds pretty.' Did Sans just compliment you? Wow.

'Um, thank you…?' You try to think loudly. Whatever that means. 'Wait, what do you mean "my voice"?'

'your inner voice. the voice of your thoughts.' Apparently it worked. 'i assume it's your true voice.'

'Oh. Cool. Great to know I still have something left of me,' you think with a bitter smile.

'but you've gotta remember something, right?' Guess it is hard to believe that you really know nothing about yourself.

'Nope. Blank slate. But... ' It's hard to put into words but you decide to try. 'Sometimes I sense... something.'

'Like if I say something about myself I can feel if it's true or not, or when I do something I can feel that I did before or if it's my first experience with whatever. Like being a monster… I'm sure I wasn't a monster before. But all these feelings are just a hunch and not actual memories,' you explain with a touch of sadness. 'I don't remember my friends, my family or how my face looks... I don't even know my own name!'

'oh,' he replies, 'that sucks, buddy... i was just about to ask for it.'

'hm. guess i'll ask somethin' different then,' Sans speaks again as you thread slowly through the foggy area that separates Snowdin and Waterfall. 'sorry for the stupid question but do ya know how old you are?'

'I don't know... Sorry, no dates or numbers. Maybe a teen?' You scratch the back of your skull, like it could help bring some of the memories back. 'Can't tell for sure. Why do you ask?'

'heh.' The image of Sans hums and closes his eyes. 'just bein' curious.'

You've gotten past the orange fish-person standing near the big blue flower and stop by Sans' second checkpoint, looking forward at your first real challenge - Undyne's "puzzle" that consists of rocks falling constantly with a flow of water.

One hit and…

You don't really want to think about the consequences. Better not get hit at all.

Wobbling through the water, you watch intently as the boulders on top of the waterfall are about to tumble out on you. It was going fine until one sneaky rock almost hit you right in the head. You manage to duck to the other side, but can't keep your balance and fall into the water. Now your shorts are soaked.

"Greeeat. " You're definitely not happy about that.

'One thing I got out of this is that drenched slippers sure aren't the best footwear for avoiding falling rocks.' You think loudly as you get out of the water and catch your breath.

'you could even say they are...' Oh no here comes the joke, ' slippery .'

You groan, much to the delight of the smug skeleton in your head. You would've found this joke funny in a different situation but not now.

'What are you laughing at? It's your reputation that will be stained if anyone sees you like this!' You pick a fight with Sans using his own weapon.

'do ya mean it would be as pretty as stained glass?' he winks at you and you give up and snort. One does not simply out-pun the pun master.

'actually, nah. i don't really care about my reputation.' He shrugs. That makes you feel a little bit sad.

'so,' Sans says, suddenly sounding very serious. 'how 'bout that deal we had earlier? i hope you're not going back on it.'

'No-no!' This question was expected and still it caught you off guard. 'I mean... Of course I'll tell you everything.'

'well then.' His hallucination-like image fixes its gaze at you. That smile of his is plastered on his face as usual and yet you feel tension seeping out from him. Or maybe it's your own anxiety. You aren't exactly sure. 'i'm all ears.'

You stand still for some time gathering your thoughts. A small group of monsters walk past you, minding their business.

'So... ' you begin hesitantly, 'As I already told you, I don't remember anything about me. But... I do remember everything about one little game called Undertale.'

'and how's that connects to anything?' Sans asks, confused.

'In every possible way, Sans.' He lifts his brow bone at you, clearly not getting where are you going with this.

'Because you're in this game.' you explain. 'All of you. Or, well, at least the majority of important monsters of the Underground.'

Sans falls silent and you continue your walk, letting him digest the information.

'go on,' he urges you after a few moments.

'It starts with the story,' you talk as you go forward, 'You know, the one about the war and the barrier but there is also part about a human child falling down Mt. Ebott.'

'As the player controls the fallen child, they make their way through the Underground, facing monsters that inhabit the place. ' Sans listens quietly, without interrupting.' Sparing them, befriending some of them or…'

'It's... hard for me to tell you that but I promised I would tell everything and it's important, so...' you are nervous. You're pretty sure Sans wouldn't like what he's about to hear. 'Yeah... The player can be peaceful or... fight and even kill every single encounter.'

Your vision of Sans is now obscured by darkness, like he has cut off all contact with you. It sends a shiver down your spine and you welcome the brief distraction in the form of a flower bridge puzzle with open arms.

The flowers are pretty and smell nice but they are also huge and heavy. As you struggle to lift one of them up you feel tension around your skeleton arms which could've been from muscle tension if you had any.

"How odd…" you mumble, wondering if this is the skeleton version of muscles but made out of magic.

'yes,' you hear a sudden response, 'it is.'

At least Sans is talking to you, that's a good sign, right? 'Do you want for me to continue?'

'sure,' he says blankly.

'So the player is greeted by a flower, who turns out to be evil and then saved by a nice lady... Oh, yeah!' You got a bit excited. 'You know her! It's that lady behind the door!'

'you mean toriel?' he asks, curiosity making its way back to his voice.

'You know her name?' It's a bit surprising to you, considering that they properly meet only at the end of the game.

'and you know even about that? huh.' Sans hums thoughtfully. 'we didn't exchange names, yet, i just... made a wild guess. turns out i was right.'

'how much information is in there exactly...?' he mutters, looking away.

'A lot and not enough at the same time,' you respond and then continue your tale.

You decide to start with describing the pacifist run, because you still shiver from Sans' reaction to the possibility of hurting monsters in the game.

While solving flower puzzles you tell Sans about Toriel, how adorable she is with her motherly care, pie and snail facts and how sad it was to say goodbye to her. It seems to cheer him up a bit.

As you about to describe meeting with him and his brother you enter the wishing room and your breath is swept away.

The cave is so big and dark you can't make out the ceiling. But it's the darkness of the local replacement of the sky that makes the twinkling of the huge, faraway gemstones looks like stars. So alike and yet different; special and unique in their own right.

'like what ya see?' Sans asks you, probably watching through your eyes too.

'It's really beautiful!' you reply to him excitedly. 'Amazing even! I always wanted to see it but it's even better than I imagined.'

'heh, well.' He smiled, maybe a bit more sincere than usual. 'good for you.'

You gaze at the gemstones for a bit, listen to the echo flowers whispering quiet wishes and move towards the wall blocking your passage. You remember that you need to check it, but how would you do it in real life? Unsure, you put your hand on the wall and slide it down until something clicks and then the wall just... disappears.

"Huh." You flinch away in surprise. 'Magic's weird.'

Then you enter a room full of stone plates with monster history engraved on them. You read few lines here and there.

'Yep. I've read this before,' you think, eyeing the unsettling picture of a monster with a human soul that vaguely reminds you of Asriel.

'so you tellin' me that this game... is an exact duplicate of the underground? ' Sans asks in a tone you can't really sort out.

'Mostly, yes. As far as I can compare right now,' you answer. 'But there are differences here and there. Though they are minor and, well, it's a simple pixelated game. Not much room for details.'

'i see,' he responds and you go back to searching.

You look for a way to get across the water but the little raft is nowhere to be seen and without it, you're stuck in here.

When you start to consider swimming as a method to get to the other side, a big round blob emerges from the water. The pink face bears such cute, anime-esque expression that you barely hold back a laugh.

"Three gold for the ferry," the face says in a funny high-pitched voice. "Hop on!"

You cautiously step on the pink monster and they dart away so fast that you're on the other side in the blink of an eye.

As you climb on to the little wooden piers, the blobby monster gives you three coins and says, "Thanks for stepping on my face!"

'Monsters are SO weird,' you think, shaking your head.

Feeling a bit giddy, you finally get to tell Sans about encountering him in the game. He hums thoughtfully and it sounds like he's pleased by his depiction.

'and then rimshot? really?' he laughs, when you describe the scene where he puns with Papyrus. 'heheh. it does sounds like somethin' i would come up with.'

You got past the cheese stuck in a magical crystal, Sans' pranking telescope and nice cream guy cove, all while talking about your in-game adventures in Snowdin.

Blue. The color blue everywhere. In the gemstones shining around and above you, in the brightly glowing cyan water beneath your feet and in the whispering azure echo flowers blooming all over the place.

It's so calm. So pretty. It looks and feels like you've ended up in a fairytale.

Which is kind of true if you think about it. You walk through wonderful scenes, talking about your favorite game with a really cool guy you never thought you'd actually meet.

It would've been like a dream come true under different circumstances but like this... you can't relax and enjoy yourself. Well, maybe a bit, but not fully.

'hm. y'know what,' Sans breaks into your thoughts. 'i think i get the gist of it. this game is disturbingly close to reality.'

'but can you just fill me in on the most important information?' he asks after a slight pause, 'and leave, uh, small details for later?'

'Oh, you are right... I don't have to tell you stuff you probably know already.' You suddenly feel dumb. 'My bad.'

'heh. that's alright. you're talking 'bout me and my brother so excitedly it's hard to tell you to stop.' he chuckles. 'hm… now, i understand when you talk about my bro. he is the best and the friendliest guy ever... but what's so good about me?'

You feel a strong urge to tell him everything, but decide to tease him a little bit, 'Are you asking for compliments?'

'hehehe.' he laughs. 'nah, i'm just curious, really.'

'Too bad! Because you're getting compliments!' You're rewarded with a surprised stare.

'First - you are funny. It's fun to be around you! Second - you love your brother so much, it's completely adorable! Third - you are mysterious, as you do and know stuff that is strange even by monster standards!' Your rant makes Sans uncomfortable but in a nice way.

'And the last thing...' You stop, pondering on the touchy subject you're about to bring up. 'You... Well. You are like a hero in the game. The last line of defense for everyone.'

'now that's just ridiculous.' he chuckles but you clearly feel the strong wave of worry that isn't your own. 'I hate to crack your theory but i'm just a simple egg head.'

'I have to disagree. You are egg cellent,' you play along before turning serious. 'But really. If the truth is anything like the game... Then I know that you can teleport, that you are very, very strong if you want to be and you even have some sort of a secret weapon called Gaster-Blasters, right?'

During your speech Sans looks very nervous. Sweat dotting on his skull, pinpricks of light shifting left and right but at your last words he just stops. He freezes as his eye sockets turn pitch black and you're struck by a sudden burst of headache and fear.

'How Do You Know That Name, Human?' That voice makes you slide to the ground and curl into yourself, trembling under the look he gives you.

'I-t-t's i-in the game f-files...' you respond, shivering and stuttering when you're finally able to speak again. Sans can sure be freaking terrifying if he wants to!

The pain in your head is unbearable and the image of Sans flinches and grabs his head. Looks like he's struggling with the same pain.

'how could i forget... how could i...' he mumbles quietly as the waves of pain slowly die down. Sans doesn't appear threatening anymore, just really confused and sad.

Something squeezes in your chest, probably your soul, as you want to hug and reassure this poor guy. You don't even care that he scared you to death just a minute ago. 'D-did I say something wrong?'

'no... no. it's okay.'He sighs and looks at you apologetically. 'sorry i scared you. but... how? how do you know this stuff? how can it be in this game-thing?'

Sans is so lost right now, you've yet to see him so shaken, 'Um... Well. Teleportation is hinted here and there in the game, like Doggo saying that you disappear without moving and the other stuff...'

'Remember I told you that the player can fight monsters in the game?' You hesitate for a bit, you don't really want to talk about this. 'You see... If every single monster in every single area is dead, the player has to face you in the last corridor. And only then and there will you actually fight by using weird attacks that weren't anywhere in the game beforehand... Including teleportation and blasters.'

'But!' you blurt out before Sans gets a chance to say anything. 'I never did that! I never killed a single monster, well... not on purpose. I watched other people do it, because I was curious and...

'Ugh, I know! It's not better at all! I'm so sorry...' An awkward silence settles in for a while as you take a stroll down guilt road. These characters felt real and alive for you even before you actually find out that they ARE very much real and alive, which only boosts your sadness from witnessing them dying.

'you know...' Sans says, after few minutes that felt like hours to you. 's'not a big deal. it's just a game.'

'You know it's not just a game!' You shake your head. 'It's all as real as it can get, now I know it for sure.'

'don't beat yourself over it, pal. you didn't hurt any monsters for real... right? so that's somethin'.' There's logic in his words and now you feel bad for making a scene over nothing.

'Ugh, I'm such a turd. I'll stop moping right now.' You get up from the ground and shake off some dirt from your borrowed clothes.

'no worries,' he says, even though he keeps sending you waves of worry. 'now i would really like to hear what you know about... Gaster...'

'Sure thing, Sans. But I don't know much...' You try to recall everything you found on the game wiki or hear from people online. 'Doctor W.D. Gaster. Probably Wingdings Gaster, but there was no proof of that. According to his followers, which are really hard to find, he was the previous royal scientist and created the CORE before... Before he fell into his creation and his life was cut short.'

Sans is holding his head looking down, expression unreadable. You feel pain build up in your head again.

'Do YOU know him?' you ask cautiously.

'i... i don't remember.' He's shaking, struggling with something. 'i'm trying to, but it just gives me a headache...'

'so that's why...?' he mutters to himself. 'it feels very important...'

'I'm sorry that I made you feel this way...' You hang your head.

'don't be sorry.' Sans tells you firmly. 'actually... thanks. it's a good thing. i don't know why, but... uh, never mind.'

'No problem.' You smile a little smile in relief.

The road forward brings you to the small gap in the ground filled with water of unknown depth and you don't think you can make this jump with your short legs. The only creature you can see nearby is a small yellow bird.

You look at the bird and then back to the gap and recall something.

"Hey little buddy." You crouch in front of the bird. "Can you help me get across?"

That bird must be very eager to help, as it immediately flies to you, grabs you by the collar of your jacket and carries you across the water, struggling, but not letting go.

Your feet touch the ground again as the bird lands in front of you. "Whoa, thanks! You're awesome!"

The bird hides its beak under its wing shyly, 'Such a cutie.'

Making your way near the garbage dump you see Aaron and Woshua splashing each other playfully in a nearby pool of water. Looks like they're having fun.

You notice something and come to a halt.

'Sans? Can you see this?' you ask nervously.

'huh? what is it? i don't see... 'he stops abruptly. 'what the... is that a human?'

In the shadows of the giant piles of garbage there is a silhouette of a child. You decide to come closer.

"Hey, kid. What are you..." you start to talk while slowly approaching tiny figure and then immediately burst into laughter.

It's just a lamp.

God damn "conveniently" shaped lamp!

You can't stop laughing and soon Sans joins you too. You both stand there laughing, foiled by a piece of furniture and somehow being happy about it.

'I can't believe this thing is real and WORKING,' you think after you calm down enough to think straight.

'i know right.' Sans responds, smiling widely. You are happy he's feeling fine again. Or at least you hope he does.

After that silly episode your journey brings you to the shop of Gerson. You hear voices coming from the inside and stop to listen for a moment.

"Wa ha ha!" It's clearly Gerson talking. "To tear a tank in half you first need to get close to it! And I bet it wouldn't be easy."

"Ngah!" And he is clearly talking with Undyne, "Then I'll just stuff it with spears from afar!"

You aren't sure if you should laugh or be terrified at Undyne's determination to go against a tank.

'hey, buddy. eavesdropping is not cool.' Sans nudges you, but he doesn't sound angry.

'Hah. Sorry, you're right.' You back away from the cave. 'You're like my inner conscience.'

'i guess i'm a bit like a conscience... either sleeping or chewing.' he laughs, but somehow this joke just makes you sad.

'Don't say, that Sans. I know you are better than this.' He doesn't respond.

Looking around you notice a pathway down to the water. There is a boat floating there. You made a mental facepalm. 'River person! I could've at least TRIED to look for them in Snowdin! Ugh!'

Irritated by your short memory, you walk closer to the figure standing on their boat. At least you can use some help now to get to Hotland a bit faster.

"Tra la la. Hello. It's a nice day for croquet... but so every other day." Their voice sounds strange and muffled, like their mouth covered with a rag. "Care for a ride?"

"Uh. Hi." You try to put up a convincing smile and climbed on board. "How about a trip to Hotland?"

"Off we go," and with that boat start to move on its own. What can you say? Magic.

"Tra la la." River Person start to sing after few minutes of traveling along. "Don't trust the man who speaks in hands."

This phrase startles you, "W-what do you know about this man?"

"I..." they hesitate for a bit. "I don't remember. But it doesn't really matter."

You feel like yelling at them that it matters very freaking much, but decide against it.

'why so rattled , buddy?' Sans probably sensed the outburst of your emotions. 'what's goin' on?'

'There was a theory...' you sigh, bracing yourself for more headache. 'That Gaster is the man who speaks in hands. Because there's a secret message hidden in the game files. It's written in wingdings. A font that uses various symbols, including pictures of hands.'

'so there's more information?' Sans is frowning at you. 'what does this message say?'

'Yes. Sorry I didn't tell you earlier but I can't be sure it's relevant... It's all just theories,' you reply, still feeling a bit guilty. 'I don't remember exactly how this message goes,but it's something about darkness growing even more darker and that the next experiment seems to be very interesting. And also there is a question in the end "What do you two think?" I always wonder who these two could be...'

As you predicted, the headache starts again. It hurts so much you hunch under the pressure. You just hope that the River Person didn't notice that.

The rest of the way goes in silence and much to your relief the headache stops fairly soon.

"Come again some time. Tra la la," cloaked figure says in a sing-song tone as you leave the boat and press forward.

Heated air blurs your vision, but you still can see lava and scorched earth everywhere with no sign of grass or trees. It feels silly to be wearing a jacket right now, but you don't actually feel the hot temperature that surrounds you. It weirds you out that monster skeletons can in fact sweat, but apparently not from the heat.

Listening to your body you suddenly realize that you feel weak. There are also some other strange feelings that you never experienced before. You panic. 'Sans, help! I don't know what's going on! Why am I feeling weird?'

'hehehe.' He laughs at your reaction. 'it's a thing called hunger. you haven't eaten anythin' aside from that spaghetti, have ya?'

'No...' you feel ashamed. How could you get scared of hunger? But then again, it doesn't feel like the hunger you're used to.

'then go get some hot dogs at my stand or whatever.' He shrugs.

'You said you're not going to help me...?' you ask curiously. 'Not that I'm complaining.'

'well. it's my body after all. do ya think i wanna die from starvation?' he says, eyes closed.

'Sorry. Dumb question.' You feel a twist of guilt again.

You backtrack for a bit to find a checkpoint-slash-hot dog stand. After a brief search, you discover few boxes with buns and... water sausages? 'Sans... are you sure these are edible?'

'too scared to try? don't have the guts for it?' He winks at you.

'Very funny,' you roll your eyes.

Bracing yourself for a weird snack you take a bite out of the combination of bread and cattail stalk. It turns out to be almost tasteless and just a little bit grassy, but with ketchup it tastes alright.

After stuffing your face with few more hot dogs you instinctively grab a bottle of ketchup and take a swig of it. Then you freeze, realizing what just happened.

Looks like Sans' body dictates its tastes to you, as you aren't sure that you were into drinking condiments before. It's actually quite unsettling.

With a new fit of energy you decide to talk a bit more. Not like you have anything to do on your final push to the castle anyway.

'Sans,' you call him just to hear a sleepy hum in response.

'I didn't finish telling you about everything I know. There's some very important stuff left. But, um…' You hesitate after hearing a yawn, 'If you want to sleep I'll leave you to it.'

'nah. i'm listenin'.' The image of the small skeleton appears in your head again. You didn't even notice that it was gone before.

You talk all the while as you walk and ride the elevators. There's nothing stopping you as the elevators are functioning properly without Alphys tinkering with them. You tell Sans as much as you know about everything. About Flowey and Asriel, about Frisk and Chara, about bad and happy endings.

This time you don't get much reaction out of him, just some unreadable emotions stirring on the outskirts of your mind.

'And I'm about to give you the happy ending you deserve!' you proclaim proudly. 'I did it in the game and now I can do it for real too! Can you imagine that?'

'yeah...' looks like Sans is lost in his thoughts. 'this is nuts.'

'Do you still think I'm lying?' You can't blame him, all the things that you've said are probably shocking to him.

'honestly? dunno.' he shrugs. 'your information gives me a lot of puzzle pieces and i'm thankful for that but i can't be sure that all of this is correct... you get what i'm sayn'?'

You sigh, 'I guess so.'

The last corridor. You've made it. The next stop is the throne room where you hope to find king Asgore.

It's beautiful in here. Warm yellow light filling everything through the stained glass. Huge white pillars standing strong. Cheerful chirping of the birds can be heard from the outside. Smells like the garden that is waiting for you in the next room

It's beautiful, but it's also unnerving.

Sans is worried about something too, you can feel that. 'listen, buddy. are you sure you wanna do that? i still have a ton a questions for you and...'

'A skele -ton?' you interrupt him.

'heh. yeah,' he chuckles.

'Look, Sans, I know what I'm doing. I'm going to free everyone today and after that, maybe we can both regain our lost memories. I have a mighty hope that the power of seven human souls will help us with that,' you say with a inner voice full of determination.

'i dunno 'bout that...' he mutters but he is powerless to stop you.

'King Asgore is so big and fluffy.' That's the first thought that comes to your mind as you see him for a first time.

The king of all monsters is sitting on the throne right now. So grand and regal with his crown and horns shining in the rays of sun that are seeping through the cracks in the mountain. He is thinking about something, looking at the flowers beneath him.

You put up the best fake smile you can and cough to gain his attention.

"Oh." He raises his head to look at you. "Howdy, Sans."

"Do you have a business to discuss with me?" he continues as you're stuck thinking if you should call him "your majesty" or not. "Wait, don't tell me! Let's go to the kitchen and we can discuss it over a nice cup of tea."

"That sounds nice," you reply with a smile that turned sincere. He is a good guy after all. It's hard imagining him killing kids... Not that you want to imagine that at all.

Now you're sitting in the chair, fumbling with a cup of sweet-scented tea in your arms, when you realize that you lied to Sans. You don't actually know what you are doing.

"So, what brought you to me?" Asgore asks you friendly and you really don't know what to say to him.

Suddenly, you recall one small but crucial detail.

If you remember correctly, monsters can release captured souls at will. At least Asriel did it in the game. So Asgore has no reason to give you the rest of the souls. If you say that you have a human soul right now, he will surely ask you to give it to him so he can break the barrier, just as he promised to his people.

A drop of sweat slides down your skull, the edges of your fake smile twitching.

It might be false but you don't want to risk it. Sure you want to free all of the monsters but there has to be another way. You don't want to die and you don't want to be Asgore's prisoner for god knows how long. You have to think of something else.

Your gaze darts across the room. Awkward silence is buzzing in the air as you try to come up with something, anything that will get you out of this situation and then your glance catches a vase with yellow flowers in it. The flowers originating from the surface.

You finish your tea in one big gulp and put the cup back on the table.

Now you know what you must do.