Sirius watched the thin woman moving about in the kitchen, his eyes a burning hatred. He moved and at that moment his elbow was grabbed by someone. He quickly threw a punch out but was blocked by an enraged Severus. The other man quickly Disapparate the both of them away from Privet Drive.
Sirius pushed himself away from Severus just as they landed outside Hogsmeade, "Bastard!" He lunged furiously at Severus, teeth bared like a feral beast. Severus quickly pointed his wand at the other man and cast a petrification hex; Sirius fell forward like a board. Sighing and looking around to make sure that they were alone Severus quickly Disapparate the both of them from the spot before anyone was the wiser.
They appeared to a graveyard near Hogsmeade and Severus took out the vampire fang that was the key to Halloween Town that Jack gave him after he left Draco with them for the summer while things settle down here in the Human World. Opening a tomb's door, they slipped inside. Once emerging outside, they were met with a disappointed Albus and a furious Minerva.
Rewinding the moments that lead to their current situation, it was mid-August and they have decided to escort Harry and Draco to get their school needs in disguise. Sirius had opted to distance himself and refused to talk to Albus after exploding at the man and accusing him of terrible things. It had broken the other man's heart but he knew he deserved the anger and rage coming from the anguished wizard. He had also accused the others of letting Harry to die for the so called 'Greater Good'.
He never looked at Harry Skellington and it seemed to the boy that his former Godfather will never be able to accept him. Harry had felt a terrible sadness from the man's careless action toward him and several times Draco had to find the boy something to distract him with. This was because upon discovering that Harry was two years younger than him emotionally due to his death and resurrection, Draco had taken the role of the older brother. He had written a letter to both Neville and Ron about the recent discovery as to why Harry can be quite childish at times.
Their replies were extremely hilarious since Harry at school always seemed more mature than them, especially when it came to seeing a person for who they are, like his relation with the late Hermione Granger.
As for how Sirius had gotten out of Halloween Town; he had sneaked after them when he heard that they were going to the Human World. By the moment Jack had contacted them through a Hag that Sirius was missing, Severus was both furious and quick to act. His guess that Sirius would go after the remaining Dursley was right on spot as the disguised Potion Master caught the Animagus just outside the Dursley's home.
Minerva released Sirius but kept his body locked in the sitting position as Severus paced in the Skellington's kitchen, "What were you thinking?!"
Sirius snarled, "Their son should die too! They killed Harry! It's not fair!"
Minerva shook her head in disbelief, "They have lost their husband and father at the same time that Harry was adopted! What more do you want for them to feel?"
"I WANT THEM TO HURT LIKE I DO!"
Severus slapped him, causing the screaming man silent. Sirius glared at him as the rest of them fell silent at the sudden lash. Severus sneered, "Get your head out of your arse, Black. Not everything is about you!"
Sirius spat the blood that seeped out from the broken cheek wall inside his mouth, "What would you know of loss? If it wasn't because of you, Lily and James would still be here! If it wasn't because of you, Harry would still be alive!"
Harry frowned at that. Sirius always spoke as if Harry had really forever died and not standing in front of him. This enraged Draco who screamed back him, "Don't talk like he isn't here! Can't you see what you are doing to him?!"
Sirius yelled back, "Shut up, Malfoy! You, your father and your bitch of a mother are all murderers! Death Eaters, scum of the Magical Society! What would you know of taking care of someone's feelings other than yours anyway!?"
Draco felt as if slapped. He, like Harry, had wanted to know what would have been his uncle and someone who understood what it was like to not being the perfect son. But again and again Sirius had rebuffed both him and Harry. His eyes pricked with tears, "You are a right bastard,"
Sirius laughed manically, "The bastard one is you!" He bared his teeth at him and Harry, "You and that sorry imitation over there!"
Jack's voice was like thunder over the sudden cacophony of voices that screamed and scolded Sirius while Albus was quiet at the table with Sally who looked angry at Sirius's description of her son, "SILENT YOU FOOLISH HUMAN!"
They fell silent as the kitchen became sweltering wit heat and Sally quickly pulled the children away from Jack. She quickly closed Draco's wide eyes, "Hush, don't look at him,"
What stood in the middle of the kitchen, towering over them was Jack. He stood tall and was on fire like Harry when mad but Jack's appearance was far more frightening and no words can describe the fear it invoked in others who saw him. This was the true Spirit of Halloween King. The kitchen darkened and Severus pulled Minerva behind him and stood beside Albus who had taken a position to shield Sally and the boys, both wizards' wands at the ready to cast a strong shield while Minerva kept her wand by her side.
They have heard of the Nightmare King, the Fright Champion but the humans after meeting Jack thought that it was simply titles. Unfortunately those titles were given to the one who embodies the very spirits of Halloween and that was Jack. A chummy and an amiable character on normal days and an exciting fellow to be around on Halloween, Jack was a force to be reckoned with when angered.
Flames licked and slithered around his body like living flaming snakes and where his skull was were a ball of fire. His tall frames were shrouded in black shadows and smokes, dark spirits screamed and shrilled as they circled his body like a black cloak. Black skeletal fingers like claws pointed at Sirius as the flaming ball opened black holes for eyes and a slit for a daggered mouth appeared, "Silent human," The voice were dark, rumbling and echoing, filling the air with tingling goose bumps. Draco whimpered as he heard the frighteningly cold voice, colder than even Lucius on a bad day.
Sirius almost swallowed his tongue as he stared at the legendary Pumpkin Demon.
Jack continued, "I have enough of your tantrum. I do not mind you keeping to yourself as you mourn what you have lost but to push away the generosity of the people who aided you and who wished to know of you," He gestured at the frozen wide eyed Harry and the shivering, crying Draco, "It is beyond childish and inhuman of you,"
The shadows around the kitchen circled and frightening faces leered at the occupants. Minerva was close to fainting and Severus was barely holding onto his emotions in check. Albus was pale but holding strong though his breathing was erratic. He knew what Jack was but never expect to see the true form of the Halloween Spirit in person. This was certainly an ally worth having and he thanked all that's hallow that Jack had ceased being the soul hunting spirit that he once was and became an amiable fellow both respected and loved.
There were lore that said that Dementors were once human but had their soul taken by the Pumpkin Demon. They cannot be killed and can only be shooed by a well-placed and well-charged Patronum. Albus could see the reason why people in the past believed so from Jack's current appearance; a burning demonic figure shrouded in a cloak of shadows that resembled souls black from spending its time so close to the hellfire that licked at Jack's body. As for the sensation that he gave? Albus would ask for the whole population of Dementors any day.
Jack continued, "You will and shall straighten yourself and you will remain here in Halloween Town as you do so," The head made of flames closed itself to Sirius sweating and pale face, "Do you comprehend me, human?"
Sirius nodded, "Yes…sir…"
Jack pulled away and nodded, "That will do," He then added, "There will not be a third chance for you. You will wish I have left you to be sucked by the Dementors when I am done with you should you break your promise,"