In a universe where nobody dies, nobody ages, and nobody can leave, he needed more than his Butterfly. He knew he promiced her all of his life, but he never realized it would be so long.

When he first mentioned a new “play” thing, She went along with it with a smile.
But after a few decades, the harem kept growing, and Butterfly was growing impatient.
She searched for ways to get rid of them. All of them.
In the end, she lost herself so far in the code, the Master thought he lost her.

But she made it. She created Hell.
For all his prostitutes to live all the misery they ever experienced, again, and again, and again.
And then return them.

Just so she could watch them die.