It was supposed to be a normal job for Moriarty.
A Satanic Cult was causing trouble…and of course, it included a few nobles. They apparently were using children from the slums as human sacrifices to summon a demon.
William didn't like it at all and neither did his brothers, so he accepted the job.
A red moon's light filtered through the only window. The basement that was the sight of the ritual was covered in blood, both fresh and dry, surrounded by candles.
Louis and Fred rounded up all the children that were still alive, taking them outside while Moran and Albert shot all the cultists dead.
As for William…he hears something. 'A voice?'
"Did you summon me? …Or, are you just here to clean up?" says a child-like voice.
William looks around, his red eyes darting around, looking for where the voice is coming from.
Then, in the corner, he saw glowing red eyes staring back at him.
In the next moment, William was sitting in a chair alone…with this thing.
"Just...what are you?" he asks, blinking to adjust to the light.
"A demon. One that was at the center of the fire that burned London to the ground," the figure now visible. It's a child or young teen with greyish blue-black hair and red eyes…that turned peacock-blue in a moment. What stood out to him was that he was well-dressed…like a noble.
'A demon, huh…'
"Your name?"
"James Moriarty, Crime Consultant."
"Tell me…just what do you want? As a demon, I can make any desire of yours come true…for a price, of course."
He takes a moment to consider it.
"What I want," William smiles, "Is to purge all the evil nobles, and change this twisted society, this world; to rid it of the class system…even if it means orchestrating my own death."
"Ptfff...ah-hahaha!" The demon laughs at the irony of it all. He used to be the Queen's Watchdog, an Aristocrat of Evil that did the Queen's dirty work, all to maintain the very class system this man wants to destroy.
After laughing for some time, he finally gets a hold of himself before asking, "Interesting. How about you make a contract with me?"
"What does that entail?"
"My service in your goal to change this twisted world, to grant your wish…in exchange for your soul."
William thinks about it for a moment before asking, "May I ask, what you did in the past? You seem...too smart for a normal noble turned demon."
"My name was Ciel Phantomhive," the demon smirks, "I was called the "Queen's Watchdog". I took care of any trouble Her Majesty was worried about."
Having heard the stories and rumors before, William nods, "It's quite ironic then...for someone who supported the class system I now want to destroy."
"I know..." Ciel smiles, "Now, the contract?"
"I'll do it," William agrees, signing his name on the paper.
"Excellent," Ciel brands Moriarty with a seal on his left hand before branding himself with one on his eye. He puts on an eye patch afterwards.
"Now then…"
In the next moment, William was back in that basement, Albert and Louis worrying about him.
"I'm fine…" William smiles, assuring them.
After getting out of the basement, William just thinks that encounter with a demon was a just a dream… until it wasn't.
He still had that brand mark on his hand, so he put on gloves to hide it.
The next morning, a little Young Master, Ciel showed up out of nowhere along with a butler with short black hair and red eyes.
"It wasn't a dream…" William's eyes widened.
"Of course not," Ciel smiles like a child with a new toy to play with.
After entering, Ciel introduces himself and his butler Sebastian to the Moriartys and their consorts.
"Nii-san/William…" Louis and Albert ask for an explanation.
"Hahaha…" William laughs nervously, "I may have…made a contract with a real demon."
"HUH?!"
As William explains himself to his family and consorts, Ciel tells Sebastian about their contract.
Sebastian smiles, immediately interested, "Death to the Evil Nobles, huh..."
As for everything else…the rest is dark history.