Thanks for the lovely reviews on the last chapter! You guys picked up on exactly what I wanted you to, which is always satisfying, but you also all overlooked something as well. If I've done my job properly, you might not have even noticed it at all...


The Other Experiment.

With the final flick of the switch, the machine gently hummed to life. Alphys let out a sigh of relief, just happy they hadn't blown any fuses as the lights in the lab/Sans' utility room stayed on, and gave Papyrus a great big smile.

"Good job, assistant!" she beamed, holding up a spanner "Shall we give this bad boy a test run?"

Papyrus didn't smile – he hadn't in days – instead absently fiddling with the control dial in front of him. Alphys could understand his feelings: she wanted to mope and sulk as well, but she had to put on a brave face for the kid. It wasn't an easy thing to do – no wonder Sans had perfected that rictus grin of his.

Alphys walked forward, getting Papyrus' attention by placing the spanner in his hand.

"Why don't you do it?" she suggested "Let's try sending it forward by five minutes."

Without so much as a flicker of his teeth, Papyrus set the dial, took the offered spanner and threw it haphazardly into the machine. It hung there a moment, suspended in the soft white light, before disintegrating down into particles and disappearing.

"Eeyyy, it's working!" Alphys squealed, pulling on Papyrus' sleeve "Isn't this exciting?!"

Again, Papyrus had no reaction, not even interested enough to pull his arm free. Wow... Alphys really wasn't good at this, and the sight of his unhappy face made her want to cry.

They were both startled by a sudden sharp knock on the door, Papyrus bolting for it like it held the answer to all his prayers.

"Sans?!"

As he opened it, his shoulders immediately drooped.

"Oh." he sighed "Dr Gaster. Hi."

Dr Gaster smiled warmly at him, ignoring his less than welcoming hello.

"Sorry to disappoint you, Papyrus." he bid "But I did bring dinner. Good evening, Alphys dear."

"Good evening, Dr Gaster."

"Papyrus, why don't you go find us some plates and forks for this." he suggested, handing the skeleton the bag of food he had bought with him "Alphys and I will be along in a moment."

"Okay." Papyrus mumbled, devastation that it wasn't his brother at the door clear in his voice.

Dr Gaster waited until he had left, closing the door behind him before he spoke again.

"I see you got your 'time machine' working." he mentioned "It must have been difficult on your own."

"Papyrus is a great assistant." Alphys admitted, clearing up the bits of clutter that lay about "He's surprisingly smart, too – not as smart as Sans, but he takes instruction better. I-I figured I should keep him occupied, since he still doesn't want to go to school."

"Still? It's been a week already. Have you gotten him to eat properly? Is he at least sleeping at night?"

"No, not well."

"That's no good – he's going to get sick as well at this rate."

"What about Frisk?" Alphys suggested "Papyrus might feel better to have at least one member of his family around."

"Dr Odin is taking care of Frisk." Gaster said plainly "Since his children are closer in age."

"But I think-"

"Alphys," Gaster interrupted, kneeling down and placing his hands on her shoulders, looking her sympathetically in the eyes "Do you really think you can handle taking care of two children?"

The question hit Alphys on a sensitive nerve – he was right, of course, she could hardly handle Papyrus, but it still hurt. Dr Gaster was the last person to tell Alphys that she couldn't do something, so to hear it so earnestly right from his mouth...

"I-I guess..." she conceded "H-How is Frisk? Is the extraction going okay?"

"We're not getting quite the results we had hoped for," Gaster admitted, standing and straightening out his clothes "But we're not giving up – it just may take a little longer than expected."

"Oh, I see... I hope they don't feel too disheartened."

"Everything's fine, I assure you." he promised "You did such a good job on the DT extractor, there's been no issues with it at all."

"That's good. What about... well... Sans? How is he? Any improvement?"

Gaster's face twitched. He wrung his hands uncomfortably, looking away from Alphys. Her heart stopped beating, clenching painfully in her chest. Oh God, she silently prayed, please say something.

"We..." Gaster started, slow like the words were painful to get out "We should prepare for the possibility that, well... that Sans won't wake up."

Alphys let out a horrified gasp, covering her mouth to stop herself bursting into tears. This couldn't be happening! How?! Why?! He had been just fine such a short time ago! Alphys could feel herself start to shake, too many emotions rising up and overwhelming her, as Gaster put his arms around her.

"Alphys..." he cooed comfortingly "Alphys dear, please be strong. I know this is a difficult time, but Papyrus is going to need us: if Sans doesn't wake up – if he really has 'fallen down' – then we'll be the only family that child has."

"I...I... y-yes." Alphys sobbed, trying to force down the devastation that threatened to drown her "I-I-I can... S-S-S-Sans... W-what are we gonna d-do?"

"Try not to think about it." Dr Gaster soothed, patting her head "If that time comes, I'll take care of everything. You don't need to worry: I'll take care of Papyrus as if he were my own son, For Sans' sake."

Gaster wiped the tears from Alphys eyes, giving her another encouraging smile and allowing her to collect herself before ushering her into the house to eat. A few moments after they closed the door behind them, the machine flashed, a spanner falling unheard to the hard floor.


Sans knew something was wrong. He would have spikes of delirious fever, followed by uncontrollable shivering, every bone in his body feeling like it was made of ice. Concerning enough for anyone, but considering Sans was a skeleton, without the ability to even feel hot or cold in the first place... he was frightened. That was his prevailing thought. What was happening to him? During his lucid moments he thought of Frisk and Papyrus, and the experiments that were surely going on right now.

His lucidity was brief, however, and he soon lapsed back into delirium. He could just about remember the times he had woken up, conscious just long enough for Gaster to appear and force something down his throat, or for one of his colleagues to try and get him to eat, but he had no idea how long it had been. Had it been hours? Years? He honestly couldn't tell.

His eyes, his hands – they burned. His chest felt like it was ripping open. Oh, God... what was wrong with him? He had to get out of bed – he felt like he was melting into the sheets. He wordlessly called for Alphys, for Papyrus, for anyone, and begged with all his heart, but nobody came.

His nightmares were so vivid – was he plunged into darkness, or was the light blinding him like white-hot needles in his eyes? He could hear everything, all at once, everywhere, funnelled right into his ears, but curses on that terrible silence! He had to get up. He had to get up! He wasn't going to fall down! He couldn't! He had to get up!


It was very late. Everyone had gone home, leaving Dr Gaster to lock up the laboratory and skim through the data they had generated that day, which didn't take him long. The lab was so quiet at night, it was almost eerie, the only real sound the faint hum of the machines downstairs. With Alphys gone, there wasn't even the comforting far-off sound of her cartoons and tinkering. Gaster made himself a cup of tea, taking another look over the data to find any anomalies. He wasn't sure how long he was sat there in the quiet when an alarm on his phone started to beep, rousing him from his studies. He took a brief look at the screen before getting up.

Down in the observation room, Sans had woken up. In his efforts to get out of bed, he had fallen to the ground, panting and wheezing, clearly in pain as he tried to get up. Gaster watched him a moment: he still seemed... sticky. But he was determined to get to his feet. 'Determined'... Observation over, Gaster picked up a pair of gloves from the table and walked over, kneeling down beside his assistant.

"Sans?" he called "You're awake. How are you feeling?"

He responded by throwing up. Disgusting. Gaster patted Sans on the back, taking note of the panicked look on his face. There was a faint glowing in the back of his eye: interesting side effect – he'd have to watch that carefully.

"G-Gaster..." Sans spluttered, still spitting up mouthfuls of bile "Wha... what's wrong with me?!"

He descended into a coughing fit, whole body shaking like it was going to fall apart.

"You're not very well, Sans." Gaster replied simply "Don't you remember? You've been working yourself too hard, spreading too thin. You need rest, my friend."

"Pa-py... Fris..."

Sans threw up again. There was nothing left in his stomach, judging by the unnerving chalky sludge and small chunks of bone that he bought up. Gaster left his side a moment, going over to the sink and grabbing the ready glass.

"Don't worry, everything's taken care of." he assured "Didn't I tell you before that you could count on us? We're taking care of the children."

He turned on the tap, holding the glass near it for a moment, but Sans didn't seem cogent enough to notice. He turned the tap off and walked back over, kneeling down beside him with the glass.

"Time for your medicine." he ordered "Drink up: you'll feel better."

Sans winced painfully as he looked up, hardly able to hold his head under his own power.

"R-red?" he asked.

"It's medicine." Gaster swore "I diluted it for you, since you keep throwing up. It's good for you."

Sans looked like he really didn't want to: indeed, he tried once again to get up, using Gasters shoulder as a brace, but his strength failed him, causing him to fall practically into the doctors lap. Gaster took him firmly with his free arm, knowing he wasn't strong enough to resist, and tipped him back, forcing him to open his mouth.

"Now now, don't be difficult." he cooed "I'm not doing this to hurt you."

In one swift movement, Gaster poured the whole glass down Sans' throat. He started to cough and splutter, trying to throw the red liquid back up, so Gaster covered his mouth, holding his head back so that he had no choice but to swallow. Once he had, he started to cough again. Putting down the glass, Gaster held Sans tightly to stop him coughing himself to pieces. The glowing in his eye increased, as did his 'sweating'.

After a good few minutes of coughing, Sans settled down. His breathing was still laboured, painful and slow, settling only when his consciousness slipped back out of his grasp. Gaster picked him up easily, putting the little skeleton back to bed and hooking up the monitoring equipment again. Taking up the clipboard from the side of the bed, he made notes about the events, detailing the dosage and effects before putting it back. Turning around, he nearly leapt clear out of his skin to find Dr Odin stood in the doorway, looking ragged and judgemental.

"So you are dosing him with 'determination'." he confirmed "I never agreed to help you do that. I never agreed to experiment on monsters."

"Is that what you think this is?" Gaster challenged "Just some experiment? You think I would treat my own precious staff that way? My own family?"

"Yes." Odin answered simply.

"Odin... my friend... that hurt. This isn't about science, it isn't about experimenting or point scoring – it's about improving the lives of monsters."

"Sans life doesn't seem particularly improved."

Gaster stepped away from the bed, holding his hands up. Despite being taller than him, Dr Odin shrunk away as he stepped closer.

"Really think about it," Gaster urged "This 'determination' is such a potent chemical, it possesses such raw power – just imagine the good it can do for monsters like Sans: the 1HP, the magically challenged, those who have 'fallen down'. By harnessing the power of 'determination', we can change the lives of all monsters in the underground for the better!"

"Whatever helps you sleep at night." Odin grumbled.

"Don't be that way." he went on, putting a reassuring hand on the other mans back "After all, unless I'm very much mistaken, doesn't one of your own children have 1HP?"

Odin didn't reply, but the look on his face spoke volumes, all of them very angry.

"If 'determination' could help them," Gaster went on "As a father... wouldn't you do anything necessary?"

Gaster patted Odin on the back, ignoring his hate filled eyes, and herded him out of the room, flicking the light off to let Sans sleep in peace.


Dun dun dun! The plot thickens! I chopped and changed the order of these scenes a bit, but I think I got them working. Believe it or not, we still haven't seen the depths of Gasters true plan...