"So... you're a wizard?" You ask curiously.
"Yeah..." replies Sirius.
"The flying... vehicle thing... is really cool."
"Thanks."
"All Dry Land things are cool! My father was a wizard."
"What happened to him?"
"He... left, according to my mum."
"Is your mum nice?"
"Yes... a bit melancholy at times though."
"That's better than having your parents hate you for whatever you do," says Sirius with a grimace.
"Why do they hate you?" You ask. Sirius pauses.

"I don't know... I guess we just don't agree with each other..." he looks away.
You touch his shoulder, a wave of calm through him.
"Did you..?" He asks, unable to finish.
"Yeah, one of the perks of being half mermaid, I suppose."
"You 'suppose'?"
"Well, since I'm half 'witch' or something, I can't breathe sometimes."
"What do you do?"
"Go up to land. Sometimes I pass out and someone has to help."
"That's awful."
"It is. I accidentally do magic, too. Fire, under the sea. Should be impossible."
"Wow."

"Some Dry Land bloke named Dumbydoor or something talked to my mother. Suggested that I go to some school called... Hogwarts?" Sirius's eyes lit up.
"That's the school I go to!"
"Really? What's it like?"
"Amazing."

You and Sirius continue talking, till sunset. That's when he realized where he was supposed to be.

"Bloody hell! I have to go, the Potters' are probably worried to death by now." He says, standing up.
"Alright, I'll see you at Hogwarts, then?"
"Definitely," He smiles. "Bye then," you wink, jumping into the sea before the transformation happens. Sirius sees your (F/C) mermaid tail and grins as you swim away.

He gets on his motorcycle and starts driving to James' place.

As he arrives, he notices three frantic people pacing in front of the Potter mansion - James and his parents.

"PADFOOT! Where have you been?!" Yells James, running over to check if his friend was okay, Mr. and Mrs. Potter right behind him.

"I went to the sea, to think... I'm sorry I worried you," he replied.
"Come inside, hon, you can explain what happened over dinner," says Mrs. Potter, hugging Sirius.

Mr. Potter ushered them inside.

"Prongs... I met a mermaid!" whispered Sirius.
"Yeah, and I'm dating Evans," said James, rolling his eyes.
"No, really James! She's coming to Hogwarts!"
"Really..?" asked James, unconvinced.
"Come now, would I lie to you my dear Prongs?"
"Padfoot, trust me you do not want the answer to that."
"You're right, it was a rhetorical question. See how well you know me? You'd spot a lie from a mile away!"
"Sirius... did the Cruciatious charm make you go mad?"
"Of course not!"
"Hmm..."
"I'll prove it when we get to Hogwarts! Just you wait!"
"Sure, okay."

Meanwhile, you swim around your Wet World town.

"(Y/N)! Where have you been?" calls your mother, your little sister - seven years younger - Adora right behind her. Adora swims forth to hug you.
"I've been... up," you say, pointing with your finger.
"Our scouts say you were with a male human..."
"Yeah! He goes to Hogwarts!"
"Be careful... anyway, about Hogwarts..."
"Yes?"
"Albus Dumbledore, the school's headmaster, is going to take you to Diagon alley in a few days."
"Diagon alley?"
"A place with many magic shops."
"Oh."
"Can you please take care of your sister (Y/N)? I have... something I need to do."
"Sure."

At Number 12, Grimmauld Place...

"He left! Can you believe it? HE LEFT!" screamed Walburga.
"Maybe... maybe we went too far this time..." said Orion.
"The nerve of him! What a disgusting boy!"
"Walburga..."
"I BIRTHED A BLOOD TRAITOR! THIS IS ALL YOUR FAULT ORION!"
"Darling, calm down."
"Calm down! How can I calm down after this!" She got up and started pacing.
"Sit next to me, come on."
"You know what? He doesn't deserve to be a Black!" Walburga headed towards... the family tree.

"What are you doing?" Orion got up to follow her, just to see her wand pointed at Sirius's name.
"What I should have done a damn long time ago!"

A blast. Sirius was burned from the Black family tree.

Regulus woke up with a thud, falling off his bed.

Sirius had nightmares after nightmares, occasionally screaming.

The Potters were worried about Sirius's sanity...

But your heart hurt every time Sirius cried...