---(Y/n)'s Pov---

I swear that I am not the type to be irresponsible. Perhaps it is true that I do not care very much for my own health- or maybe it is that I am just very tired. But without Gaster's guidance, I completely forgot to grab my coat and scarf from Sans' room. I was in a hurry, and he was already stirring awake.

Shivering as I walked towards the Lab, having to pass through the snow to reach Waterfall was a real pain. My body had several cuts from Sans, and not to mention the sight of several bruises. The both of us really did engage in a battle for dominance, and neither of us dared to back down. Sans would have his way in the end, because he would refuse to give up.

But myself? I wanted to stop evading him. It was costing me too much energy and eventually felt pointless. Weaving around him, evading his attack and desire to mark me became a waste of time. After all, I could of been back to work in a few days with little issues rather than... this.

Now, since I ran away from him, he'd be hunting me down. I'd have to constantly look over my shoulder and prepare myself for his next assault. And this time... I doubt that I'd be able to stop him. Papyrus managed to explain to me that his more aggressive instincts were lashing out at me because I was not taking care of my body. It triggered him into a mode of protection.

To protect me from myself- how ironic.

My body shivered from discomfort after cold wind blew in my face. The next thing I knew, I was suffering from the weather. I honestly couldn't help it when I let out a small sneeze. "Wonderful, I'll probably catch a cold. Perfect timing."

Last time I got sick was after one of my heists. I left the safety of my hideout without Gaster's knowledge. Needless to say, I was young and wanted to impress him since he seemed down that day. Sure I managed to return with one of the pieces that he wanted for our project, but it was at the cost of my health. I forgot to wear a coat that day, and ended up coming home absolutely soaked.

Looking down at the snow, I wanted to smile. Almost wanted to. It was a memory that I was fond of since I was able to make the doctor both upset and content at the same time.

Shaking my head, I soon found myself entering Waterfall. I had to remember that my perception would be beyond drained from potentially becoming sick- like last time... where I accidentally tripped over a piece of wrapped candy on the floor. That was the first time that Gaster ever told me... that sweets would be my undoing.

Ugh, that man still haunts me with those echoing words. 'Beware the candy, beware its wrath.' Yeah, how it has made me mess up throughout my life. Thanks for the warning, Mr. Royal Scientist. Really appreciate it.

A small chuckle escaped from me as I reached a path of glowing blue flowers. I couldn't help but stop to crouch in front of one, admiring its beauty before I faintly whispered out in irritation. "I hope that what I am doing here brings some kind of happiness."

"Nothing will change what you've done."

Sharply turning around, my eyes landed upon Aliza's cold glare. She was giving me a look of hatred with a knife firmly held in her hands. "So, are you here to patronize me? Go away if so, I do not have time for your childish games."

She scoffed at my words, shaking her head with a small sigh. I couldn't defend myself properly against her, and she seemed to be aware of it. "You don't deserve to be alive. Me killing you will be like a bad joke, right?"

"Well, so far I'm not laughing at it. So yes, it must be terrible." I mused with a sigh. "If you take another step forward, you will regret it."

---Sans' Pov---

I stayed at home with (Y/n)'s coat firmly pressed against my face to take in her scent. In the hopes that she'd come back so I could finish what I started, I didn't give chase. After all, she would be coming back for her... warmer... clothes.... fuck.

I let out an angry growl before throwing myself to my feet. She never dared to hurt me despite how she evaded me, but I knew that I wore her down pretty bad. And right now, she was out there. Vulnerable and probably fucking sick due to her lack of care.

'Find her... find (Y/n).... find... danger... she's in danger... is she hurt... world is dangerous... everyone wants her dead... protect mate... mark...' The words wouldn't stop overlapping to fuel my anxiety.

Scratching at the crack in my skull, my primal instincts woke up almost immediately. Everything looked very differently to me, as if my eyes were only detecting Souls rather the bodies attached to them. In the past, this is how we perceived the world around us. Skeleton Monsters can still do it to heighten their senses, but it was deemed as a very primitive approach... despite being useful for seeing others through the slightest obstacle.

'Her Soul... find her Soul... Soul... lilac... mine...'

Huffing with annoyance, I stormed downstairs and immediately recognized Paps' upside-down Soul, floating out of the kitchen to stare at me. "M' gonna go and fetch her."

"ALRIGHT, BROTHER. THE OTHER HUMAN WENT OUT AS WELL, IF YOU SEE IT, TELL IT TO COME BACK HERE." He growled out. I made note of what he said, but my thoughts were strictly focused on finding that lilac Soul of hers. I was worried. Ha... hahaha.... I am worried?

'(Y/n)... (Y/n)... no one else.... just mate... MY MATE... MINE... BRING HER HOME... BACK... SAFE...'

I slapped a hand to my eye briefly, letting out a devious chuckle while leaving the house. Once the door closed behind me, my laughing self calmed down. As I pulled my hand away, my face was left with a nonchalant expression. My eye was narrowed in a serious way, but my posture screamed lazy. "Alright. I'm comin' for ya... ready or not."

'Don't Hide.... I'll find you... find... you're not safe... come back...where are you?!'

Using my magic to find her immediately told me that she was no longer in Snowdin, so I instead teleported to Waterfall and started looking around normally. I could smell her blood from what I did- or at least I think that It was my doing. Walking further into the cave, my body became more hostile to match my emotions... easily snapping at everything. 'Blood... sweet... her blood... blood.. BLOOD.... BLOOD.'

Until I heard it.

The soft echoing of flowers telling me something that seemed important. I relaxed slightly to listen to it further, telling myself that I had to wait. "I hope that what I am doing here brings some kind of happiness."

I looked around quickly, as if my Soul was searching for her presence... until another voice caused me to freeze with anger. "Nothing will change what you've done"

What has she done... huh...

"Go away-" That one was cut off by others that were overlapping each other.

"Me killing you will be like a bad joke, right?"

"You will regret it-"

"You should of-" "Ugh!" "STOP DODGING!" "WHY WONT YOU DIE!" "DIE, DIE, DIE!" "You... killed him..." "Why wont you just die..." "I hate you..." "Wait, stop!"

"I warned you. Perhaps you should of listened."

And then, it was just a repeat... I wish that I could of been here, to stop whatever the hell happened. "S-Sans?"

My head snapped around, desperately in search of that shaken voice. On the inside, my mind was telling me to ignore it... but I decided not to.

'Distraction... kill it... kill it... kill...'

Looking down, I was surprised to see a knife that was coated with blood, and once I looked up I saw something that made me snap out of my overly protective state. That other Human girl was hanging upside-down by a long rope that belonged to (Y/n)... it was her grapple. So that means-

Bringing the knife closer to inspect it, I was hit with a very intoxicating scent. (Y/n). This was (Y/n)'s blood. "Are you just going to leave me here?! She's getting away!"

My animal instincts were triggered immediately, the instincts to defend my mate. I haven't marked her yet, but my Soul has already laid its claim. And right now? Heh... I was shaking with rage. "W-Wait... you wouldn't side with someone like her? She's dangerous- she'll... she'll-"

'KILL IT. IT HURT HER! KILL IT!'

I summoned my axe without hesitation, and then brought it above my head to finish off the struggling Human. "She's a murderer! SHE KILLED MY FATHER! I NEED HER TO DIE!"

Stopping at her words, I snapped back to reality for a brief moment. "What...?"

My Soul throbbed at the thought of my (Y/n) being a killer... her knowledge, attitude and even skill all pointed into that direction.

So how did that make me feel... that the one that I love happens to be some kind of killer? A murderer who hasn't even hurt a single Monster?

My crazed smile widened at the thought as I raised my hand above my head and used my magic to roughly get the Human down. She fell to the floor with a loud thud, probably almost breaking a bone. "So then. You're sayin' that she is a killer?"

Aliza shivered under my stare before trying to get up, but offered a nod. "She's killed.... a lot of people on the surface."

"And you're aware that she hasn't touched a single Monster? That she's had every opportunity, but made too much of an effort to avoid it?"

The Human paused as I snickered. Getting out of this trap probably earned her a save point, so I didn't care much for my next actions as I raised my axe. Only to cut into her flesh and drown myself in her screaming... and blood.

'I wonder what (Y/n)'s screams would sound like.'

Cackling dangerously after I took out the frustration of seeing her blood spilt by someone other than myself... I continued on towards the Lab. A trail of her crimson liquid led me to her, and I was so eager that I found myself teleporting further.

Knowing that I was closer made a low rumble of laugher escape from me, I was about to finish this game with her. I was about to bite into her skin, and claim her as mine. "Oh (Y/nnnn)..."

"Come here... Come HERE.... WHERE ARE YOU COME HERE... HAHAHA!" I couldn't stop the crazed words from slipping away, straight out of my control.

Without hesitation, I took the elevator into the True Lab, slamming my hand on the button to go down. My eye was darting around in search of her... and fortunately, I knew that I could teleport out of here once. Walking through the halls, I continued to follow the Amalgamates. My weapon was dragging behind me, producing sparks against the floor along with an uneasy screeching sound. The creatures gave me low snaps due to the noise, while others tried to get in my way. But it made no difference, because I eventually found her.

Coming into one of the rooms that she was hiding in, my eyes fell upon her hand that was clutching a wound in her leg. She was sitting in a corner, breathing heavily. My skeletal body gave me an eerie edge with the lights just outside flickering. "Great. I don't have time for this, Sans."

My gaze darkened into a glare almost instantly upon seeing the injury. My Soul was telling me to wrap myself around her and hide her away from this damned world. That no one could see her while she was like this- that she was hurt and needed me to keep her safe. "Are you honestly going to do this while I am in this state? How am I supposed to feel about you taking advantage of this situation?"

'Hurt... she is hurt... HURT! HELP HER, SHE IS HURT! Home is safe... SAFE...' I shivered from the hostility of my own thoughts. They were everywhere, the voices from the primitive instincts of both insanity and my heat were putting me over the edge... I have to try and remain calm.

"Hah..." I started with a low growl. "This proves that you can't take care of yourself- why should I play fair? Your Soul is fucking calling out for help, even if you don't know it. And I swear if you try to fight me... I will fucking use any means-"

"You always underestimate me, Sans..." She said, however her words were cut off by a small cough. I arched a brow before finally realizing that she was also sick.

"Heh....ehehehe... I'm tired of your shit."

"Well, unfortunately... you'll have to deal with it." After she said that, (Y/n) brought her fingers to her mouth and let out a loud whistle. I stumbled back for a second, not expecting the noise. And then, my body felt consumed by some kind of sticky heavy weight. Looking up, I saw it... that damned Amalgamate dog on my back. "I'm going to go elsewhere. Have fun, Sans."

With that, she left. I struggled against the creature, not wanting to waste my teleport in case I managed to catch her. But yet again, she was fucking right. I underestimated her- but now... I was done with this. I wasn't going to be a good guy and give her space or something. No, I was going to show her a really horrible time.

"You'll regret pissing me off, (Y/n)."