They had called him Robe, as he wore long and heavy robes. Black was already taken, as was Blue, so they nicknamed him Robe. Even if Black was gone, they didn't want to call him the new Black.

He was the only skeleton who wasn't kidnapped. That was why he didn't have any chains, because he came willingly.

Did Red even realize he was the hostage?

Papyrus didn't like Red. Like Black, he was too different from his brother. Blue and Sans were more innocent, Red wasn't. The scars from his universe would never fade, as would his training. Papyrus' original Sans never meant for anyone to get hurt, which was why he sacrificed himself. Papyrus liked that Robe did that too.

Red had been the hostage Papyrus had used without his knowledge. He knew Robe the moment he had stepped into his universe, apparently having done research. Papyrus knew exactly how to convince Robe to come to his universe.

For Robe, killing was wrong. Harming innocent people should never happen, under any circumstance. After his brother, King Papyrus, had declared war with the humans, Robe had fled to the ruins. He couldn't bare to see this play out, instead trying to protect the fallen humans. He swore to never forgive Papyrus. His brother, of which he once loved, was killing innocent youth. Robe could never forgive someone like that.

Until one day, Papyrus was in the ruins.

Robe knew his brother when he saw him, and this Papyrus wasn't his. He was far too different. His face wasn't aged with grief, it still looked fresh and young, like it did when they were younger. Before the war. Instead of royal attire, he was wearing some odd outfit.

And he had a deal to make.

Robe had learned of his origins from this new, alternate version of his brother. His universe was called Altertale, and Papyrus had purposefully went to this universe for him specifically. Red and Black were from bad universes, he wanted a Sans that wouldn't try to attack. That, he had claimed, was what a real Sans was. One who sat, looking cute, making puns, and never tried to kill anyone. Robe fit that description.

Of course, he wouldn't come without motivation. So Papyrus had offered him a deal. If he came to the new universe, he wouldn't be chained, and he would be saving Red's life. If he didn't, well, Papyrus had no use for Red. Robe was a caring skeleton, naturally he would agree to save a life of someone else.

That's how the fifth Sans was kidnapped. Robe, a skeleton who had stayed in the ruins to keep people safe.

So he sat on the floor, calm dementor adding some sanity to the other Sans'. There was chains for him, in case he acted out, but it was rather clear Robe wouldn't. He didn't have much in his own universe, this wasn't much different. And he swore to himself murder was always wrong, it was why he abandoned his old life and brother.

Until the doubt began to show.

Robe himself had always claimed murder was wrong. Yet he sat in the corner, watching these skeletons unfold their horrid story to him. There had been a different Sans before him, who had died trying to protect them. He died for nothing. Blue blamed himself for the murder. As Robe was right next to him, he watched as Blue slowly descended into madness and grief. They had tried simply to run away, it didn't work. Papyrus was too smart.

It made Robe question his own choices. His own brother wasn't killing people for his obsession, he was killing people for his Kingdom. This Papyrus had killed so many for one man that wasn't even alive anymore, how many more would he harm? Simply running away wouldn't work, as Papyrus would just kidnap more innocent versions of his deceased brother. He replaced Black with no problem, what would stop him from replacing everyone else? Papyrus managed to get someone to build the machine before, he could likely do it again.

This was wrong. All wrong. Robe soon realized some people couldn't be talked down, that force had to be used in certain situations. Blue seemed to be learning this lesson too. It was horrible to watch, to learn of their tale. To think Robe abandoned his brother over something so quickly, without even trying to discuss it with him.

What kind of brother was he? What kind of Prince was he? He had a duty to the people to keep them safe, but instead he hid behind his own ideologies, running away instead of facing the truth like a coward. Now he couldn't see anything but the truth, it thrusted into his face with nowhere else to turn. And so, over the weeks, as he got to know the other versions of himself and the demented version of his brother, his belief was slowly chipped down until one thing was clear.

Papyrus had to be stopped, even if it resulted in his murder.

It had been Blue that attacked. Robe had no idea how he obtained a knife, but when he turned to see his innocent alternate self standing with a knife, he had been shocked. Blue had been driven to his end, just like Robe had.

Papyrus would never suspect either of them to commit the crime, which was why both of them remained unchained. Blue was always talking about redemption, and Robe had previously abandoned his entire life over the declaration of war. It would come as a shock to find that Robe was the one who picked up the knife when Blue fell to the ground. After all, it had been Robe who sacrificed himself to come here for Red's own safety. Why would he suddenly risk that again by trying to kill Papyrus?

Because he realized what he had been doing was wrong. And he wanted to fix it.

All Robe had ever been in his life was an observer, never taking action. A fault of his own, really. He was supposed to become King, but instead Sans gave it to Papyrus, his brother. And when Papyrus acted as a King, trying to protect their people with a war to help them escape, Robe ran away from his own mess. And in the ruins, he never stopped one of the six children from leaving. They died because of him, because he simply sat back, too scared to participate.

Papyrus would never suspect him. All Robe had done here was observe, like the rest of his life. Papyrus wanted a Sans like that, one that would never try to fight back.

Unfortunately for him, he would never find one. No matter their original beliefs, if a Sans was forced into this situation, they would see the real struggles one had to face. His original brother wasn't strong enough to face the truth, and dusted as a result. Those who were strong enough to admit the truth were willing to fight back. Papyrus would never let them go unless he was dead.

And do, with a knife in hand, he approached from behind.

And it was Robe who committed the murder.

There was no satisfaction to seeing Papyrus die. The dust and blood fell down, scattering across Sans as the determination vial clattered to the ground much like the knife clattered from his fingers. They trembled harshly.

Robe had been helping Blue up when they heard the sirens. The police. They were coming.

The others ushered Robe out of the back door, giving him firm smiles. It'd be okay, all of them had agreed, we'll make sure they never find you. By the time they did solve the case, Robe would be long gone.

The skeleton had been hidden in the trees, outfit blending into the shadows as he watched his alternate versions be taken away into the cars. The police never looked for a fourth skeleton.

With one last look at the house, Robe turned.

And ran.