The walk from New Home to Hotland was a silent one. Gaster walked slowly enough that Undyne had no trouble keeping up, but he walked fast enough to make a conversation difficult.

This was intentional. He had nothing else important to say to the Commander, and didn't particularly want to hear what she had to say.

No, really he just wanted to curl up in a ball and be done with this stupid world that refused to let him have his family.

... No, that wasn't it, either.

No, he just wanted Papyrus and Sans back. He just wanted his sons.

He just wanted his s-

He stopped abruptly as a loud CRASH! echoed through the spacious Hotland cavern.

He glanced at Undyne, saw she was looking at him.

They both took off running.

As they rounded a corner into the main Hotland road, they stopped in their tracks.

Because Sans was up and about, and fighting... Sans.

The pair of Sanses quite nearly danced around each other, trading blows. One of them wore a blue jacket, and held a bone, while the other wore a darker, more purple jacket and was gripping a black rod that glowed with a Corrupt light.

As Gaster and Undyne watched, the Corrupt Sans suddenly lashed out with a kick, hitting the Pure Sans in the ribs, sending him stumbling backwards. Then the Corrupt thrust his hand upward, and the ground exploded, a geyser of Corrupt Magic shooting upward. The Pure just barely managed to lunge forward to avoid the attack.

Then they were back at it again, swinging their weapons with everything they had, hoping to take out one another.

The whole time, the Corrupt was roaring in the Corrupt language. Gaster didn't know the Corrupt language, but he had heard his captive swear in it more than enough times to recognize quite a few of the screamed curses.

They had only been watching for a few moments, but it was clear Sans, the Pure Sans, was getting tired. He wasn't using shortcuts, the Gaster Blasters, or Blue Magic, only bones, and he was struggling even with that. The Corrupt Sans, on the other hand, seemed to only just be getting warmed up.

~o0o~

Sans was furious.

He could understand his army sending in this copy for espionage. He could understand that it might be seen as betrayal that he let the Pure army have so much knowledge about the Corruption. He could even understand the copy's anger about his inquiry regarding Papyrus.

But, to refuse to tell him anything about Papyrus's location, that was unacceptable.

It had taken Sans a little while to figure out what was going on, as well as how it had happened.

But, once he had figured it out, the plan was frightfully obvious. Not that he had been afraid of it, as it was benefitting the Corrupt army, his army.

No, he had been impressed.

Because regardless of whether you built the original or your enemy did, you never let your best weapon into war without a backup.

So before Corrupting him, the Corrupt took some of his Magic, and cloned it. And now, they had another fully-functional Sans at their disposal.

Well. They had one Sans, the clone. The clone's refusal to tell Sans where Papyrus was had been enough to convince Sans, the original Sans, that he had been taken captive by the Corrupt.

And that, that was unacceptable. If his brother became Corrupt, Sans would completely lose all reason to fight for him, as it was Papyrus's love that Sans fought for.

So he had to get Papyrus back.

And step one was beat the copy Sans up until he told the original Sans which base Papyrus was at.

Lucky for him, the Corrupt hadn't figured out all his Pure Magic, so the copy was limited to bone attacks, and nothing else.

Sans batted one of said attacks out of the way with an attack of his own, which slammed squarely into the copy. He strode forward, fully intent on crushing the life out of the copy.

"W͌̓ͫͪ͏̴͈̠̳̝͞ ͦ̂̃ͬ̿̇͏̖̺̣͎̳̫͔͙̮H͊̌͋̔ͩ҉̣̯̼͉̹̟̤̥ ̶̴͉̥̩̟̫̂̐ͯÊ͓̫̍̅ͩ̓ͤ̕͜͠ ͋͊͑͏̡̗͍̜R̞̟̬̗͖̭͙͐ͯ͊͂̊̈́ ̴͓̮̳̪͆̓͌́Ȅ̥̲̩͖͇̻̭̳ͤͣ́̅̚ ̸̜ͭ̾͞ ̴̥̮͉̞̻̫̦̅ͮ̓͆͆ͭ͘͞ ͙̯̔ͫ̄̏̕Iͬ̌̓͗̍͛҉҉̤̭͙̤̖̩̯͈͟ ̡̜̞̰̩̠͓̾͂͡S̜̖͙͎̗͛̎͗͗͡ ̋͂͋͠҉̡̺̩̫̱̯͇ ̢̝͍̲̲̟͑̎̿̈́ͮͫ̒ͮ ̧̘͙̙͕͇͙̱̺̟͆ͯ̌͝M̪͍͋̊̎͐ͫ̉ ̗̩̰̱̦͙̘̗͕̈́̋̈́̒̓̉͂̀Y̻̦͎̽̈́ͯ͜ ̶̱͕̞̮̜̈̒͟ͅ ̭̝̳̫̟̺͕̈͒̒̅ͮͬ̂ ̨͇̻͙̌́̐͑̂̀ͬ̕͜ͅB̡̳͙͈̖̓̓̋̈́ ̨͚̱̏͋R̗̳̼͖̪̙̺͑̾͆̓͂͊̈́͐̏ ̰͖̑̍͆ͧ̃ͮ̂̑̚O̓ͭ͑̍̒ͦ̚͘͏͓̜͓͍̺̼̭̺ ̵̰̬͐̆ͮ́̅ͧ́T̴̹͓͛͗ͥ͐̈́̽͜ ̹̜͍̠͎͓ͦ͘Ḧ̪̬̔͑̈́ͅ ̩̫ͦͤͦͥ͘E̦͙̰̬̯̳̖͇͈ͬ̄̒ͤͨ̉̈́͛͝ ̎͛ͨ҉̺͚̠̟͕̥͉͇͟R̤̻̟ͧ̊̍ͤ̑͑̎̄́͝ ͍̳̝͖̗̰̖͋͆̇͛̄̋?̸̡͍̼̽͛"

He snarled as he reached the clone, who was struggling to get up, dazed. Sans slammed a booted foot into his ribcage, forcing him back down.

"W͌̓ͫͪ͏̴͈̠̳̝͞ ͦ̂̃ͬ̿̇͏̖̺̣͎̳̫͔͙̮H͊̌͋̔ͩ҉̣̯̼͉̹̟̤̥ ̶̴͉̥̩̟̫̂̐ͯÊ͓̫̍̅ͩ̓ͤ̕͜͠ ͋͊͑͏̡̗͍̜R̞̟̬̗͖̭͙͐ͯ͊͂̊̈́ ̴͓̮̳̪͆̓͌́Ȅ̥̲̩͖͇̻̭̳ͤͣ́̅̚ ̸̜ͭ̾͞ ̴̥̮͉̞̻̫̦̅ͮ̓͆͆ͭ͘͞ ͙̯̔ͫ̄̏̕Iͬ̌̓͗̍͛҉҉̤̭͙̤̖̩̯͈͟ ̡̜̞̰̩̠͓̾͂͡S̜̖͙͎̗͛̎͗͗͡ ̋͂͋͠҉̡̺̩̫̱̯͇ ̢̝͍̲̲̟͑̎̿̈́ͮͫ̒ͮ ̹̜͍̠͎͓ͦ͘Ḧ̪̬̔͑̈́ͅ ̩̫ͦͤͦͥ͘E̦͙̰̬̯̳̖͇͈ͬ̄̒ͤͨ̉̈́͛͝?̸̡͍̼̽͛"

The copy started to choke out a response, but something slammed sideways into Sans, sending him sprawling. As he stood, he saw Undyne and Gaster both advancing on him, Undyne holding a spear, Gaster equipped with a bone and his trademark handlike weapons.

Sans swore. An inadequate clone he could handle, but he was still shaking off the effects of the containment cell, and wasn't fully recovered from breaking out of said cell. There was no way he could take on Undyne and Gaster at the same time, and he doubted they would believe him if he told them he was the original Sans.

And if he wanted to get an answer from the clone, he'd need to put up with Undyne, Gaster, and the clone, which he simply couldn't do.

Better to leave with his life, and find another way to get what he wanted.

Sans turned tail and fled.

~o0o~

The instant the Corrupt Sans ran, Gaster hurried to his son's side and began helping him up.

Undyne, however, was more immediately concerned that there was a Corrupt monster in Hotland.

Last time that had happened, her girlfriend and Gaster's younger son had been kidnapped.

She started running after the Corrupt monster, throwing spears at him as she ran. The Corrupt Sans dodged all of these with ease, however, and continued.

Undyne started to gasp for breath, then barely managed to avoid a barrage of Corrupt attacks.

Had this been in Waterfall, or even New Home, Undyne would have been able to go for much, much longer. But this was Hotland, and Undyne didn't do so well in the sweltering heat.

The Corrupt monster began to draw away from her. She let out a roar and redoubled her efforts, ignoring the burning in her chest and sweat slick on her scales, slamming her feet against the ground with furious speed.

But then, she tripped over a rock.

And when she got up, the Corrupt Sans was gone.

~o0o~

It had to have been another day and a half, at least. Alphys was sure.

Because she had been doing nothing but sitting there and slowly burning Magic to keep Papyrus warm, and she was getting quite hungry. At the rate she was burning Magic, she had calculated, she shouldn't have begun to feel serious effects for four or five days.

And she was beginning to feel serious effects.

"P-Papyrus?" She asked quietly, as she had done every once in a while.

Papyrus moaned.

"D-do you feel any w-worse?" Alphys had stopped asking if he felt any better some time ago. She had to make sure he wasn't getting worse before trying to get him better.

Papyrus was silent for a moment. Then he moaned again.

He sounded slightly positive, so Alphys decided to take it as a no.

A few more moments were passed in silence.

Then there was a loud clanging sound, like the grinding of gears, and Alphys was blinded by a sudden light.

Blinking as her eyes slowly adjusted, Alphys saw two monsters stride into the room. One of them roughly grabbed her arm. "C'mon, on your feet."

Alphys squeaked, and complied, clutching Papyrus to her chest.

The other monster took up position opposite the first, and they escorted her out of the dark room, into a run-down corridor. The walls were made of purple bricks.

With a start, Alphys realized they were in the Ruins.

She and Papyrus were just about as far into Corrupt territory as they could be.

She swallowed nervously and followed when the Corrupt guards told her to.

They walked a long time, down one corridor and around through another, out into courtyards and back into the old hallways. Sometimes she caught glimpses of the rest of the sprawl of the Ruins. Corrupt monsters were everywhere.

Eventually, they were led into another room, and forced into a cell against the back wall. Then they left.

Alphys looked out of the cell, through the thick, reinforced glass wall into the room. With more than a little foreboding, she realized it was a lab, and the table in the middle of the room most definitely had restraints on it, and the vial on the counter opposite the cell had a dark, Corrupt liquid in it.

Alphys had no doubt that if they stayed here, they were going to be Corrupted.

~o0o~

Sans was, once again, bedridden.

Gaster looked at his incapacitated son, who was just beginning to awaken from the thrashing he had received.

Sans groaned. "whhhhngh..." After a minute, he started struggling to sit up.

Gaster set a hand on his chest, gently pushing him back down. "Shh. It's alright. You're safe; you're going to be fine."

He stopped struggling, falling limply back onto the mattress. "... wha'...?" He opened his eyes, looking up at Gaster.

"You were beaten pretty badly, by a... Corrupt version of yourself, I guess."

Sans frowned, his gaze wandering. "i... i think... i remember him... in waterfall..? ...yeah. last time i... before you found me."

Gaster blanched slightly. "You mean he's the one who left you there? But he's been locked in the lab for over a year!"

Sans looked back to Gaster. "but didn't you say i've been dead for over a year? ... all i know is that i remember him attacking me in waterfall."

Gaster's frown matched Sans'. "I... suppose that's possible..."

"it is. it happened. it'll happen again, unless i do something."

Gaster blinked slowly. "Okay. I believe you. Just rest, for now."

"i need- ..." Sans struggled to get up again. "-need to get to the warfront--"

Gaster again forced Sans down. "Okay. Later. You'll just get yourself killed if you go now."

But as horrible as Sans was right now, Gaster still felt a small flame of hope burning in his chest. Sans was remembering things.

~o0o~

Sans mentally chided himself.

He was so, so stupid.

He knew Waterfall. He knew every offshoot cave branch, every waterfall-concealed room, every echo-flower field.

And yet, he had gotten himself cornered, with a dog patrol picking up his scent some forty feet away.

If he moved, they would see him instantly. But if he didn't move, they would track him down anyway.

So, despite his fatigue from running and fighting, his best bet would be to wait until they got into range, and jump on them. There were three of them, the Dogi and Doggo, and all were strong soldiers, but nothing especially challenging... He hoped.

He could hear the soft barks and yips dogs used to communicate between them, getting louder as they approached his hiding spot. Just a couple more seconds....

And a few more...

With a roar, Sans lunged over the rock, a Corrupt, sword-like weapon in his hand. The trio of dogs all looked up at him, shocked.

He was on them in an instant, slashing out with his weapon. He caught Doggaressa across the chest with a powerful blow that sent her flying back. Dogamy immediately dropped to the defensive, trying to protect his downed wife, not leaving her side.

That left Doggo, then.

He knew that if he didn't move, Doggo wouldn't notice him, but while Dogamy was still standing protectively over his downed wife, he was barking to Doggo, no doubt telling him where Sans stood.

So as Doggo lunged forward, Sans leaned back and twitched his hand upward. Nearly black tendrils of Corrupt Magic burst out of the ground, wrapping around Doggo and flinging him to the side.

With Doggo out of the way, Sans started running.

He would have liked to stay and finish of the dogs, but his brother was in danger, and he had no time to spare.

§

A/N

So has anyone else ever thought about how hard it must be for the dog monsters in the Underground to name their children? I mean, how many dog-(suffix) names can you come up with?

Anyway, thanks for reading, and I hope you enjoyed it! Your comments and votes are the two biggest motivators for me to keep writing!