London, Grimmauld Place.
The Black Family's ancestral home was hidden here.
It clearly hadn't yet been used as the Secret Headquarters for the Order of the Phoenix, and likely never would be in the future.
So, while it was also hidden from Muggle view, it hadn't yet been placed under the Fidelius Charm.
"You've never been back here before?" Arriving at the door of Number Twelve, Grimmauld Place, Severus looked down at Sirius.
Sirius snorted coldly.
"I don't consider this a place worth reminiscing about." Soon after, he couldn't resist adding a sarcastic jab, "Though the old you would have probably loved it here, as it was once home to a bunch of like-minded individuals."
Severus didn't confirm or deny this. He simply stepped forward and pushed the door open.
"Perhaps."
They entered the Black Residence, stepping into a hallway that was almost pitch black. It smelled damp and dusty, with a sweet, rotting odor.
The place felt like an abandoned, empty house, yet it was also unnaturally tidy, with not a speck of dirt visible on the floor.
A row of old-fashioned gas lamps on the walls flickered to life, casting a wavering, unreal light on the peeling wallpaper and worn, threadbare carpet in the long, gloomy hallway.
A cobweb-covered chandelier overhead glimmered faintly. Crooked, aged portraits blackened with time hung on the walls.
Just as Sirius was about to lead the way further inside, the old carpet on the floor suddenly flew up!
It rose like a large sheet caught by the wind and slammed down over Sirius, then rapidly tightened, binding his body!
Simultaneously with the carpet's movement, a coat stand beside Severus also began acting unusually. It seemed to come alive, lunging towards Severus.
However, Severus simply extended his wand and tapped the coat stand lightly. It instantly became an inanimate object again, clattering to the floor. Sirius, less fortunate, was shouting mid-air, his cries sounding particularly shrill through the radio on his collar.
"Kreacher! I know it's you! What are you doing?! Attacking your one and only master now!!"
By a wall-mounted gas lamp, a small figure had appeared at some point.
Its face, covered in wrinkles and as aged as a rotten orange, was full of hatred and disgust.
"Intruding thieves! Kreacher has no master anymore! Kreacher's last master gloriously served his worthy master and was honorably imprisoned in Azkaban! You thieves! Kreacher won't allow you inside!!"
It shrieked, clearly furious.
Seeing it appear, Sirius became visibly flustered and angry.
"You think I'm like the others in this family, loyal to Voldemort? You haven't read the recent news but believed what those people said before! Kreacher! Let me down! I know you can sense it, you could never mistake a member of the Black Family! Now, I order you as your master! Immediately! At once!"
Hearing Sirius's words, the old house-elf's body trembled. Its large eyes noticeably began to dart away, but it finally raised a finger, making the carpet loosen and lower Sirius to the floor.
Sirius's anger, however, had not subsided. He glared with his dog eyes, staring intently at Kreacher, who refused to meet his gaze.
"You recognized me the moment we entered! Didn't you?! No matter what form I take, you could never mistake me!"
Kreacher avoided his eyes, loudly defending itself.
"Kreacher couldn't imagine Master Sirius turning into a dog! No one in the Black Family would ever do such a thing!"
Then, its face towards the carpet, it muttered in a voice it presumably thought was inaudible, but which everyone could hear clearly, sounding like a grumbling bullfrog.
"Shame of the family... My poor Mistress, if she knew Kreacher let such a dog, defiling the Black's name, inside, what would she say to Kreacher? Such a disgrace, but what can Kreacher do..."
"Don't think I can't hear you!" After saying this, Sirius had clearly lost all interest in communicating with the house-elf.
He turned to look at Severus, who had been watching the spectacle.
"If you want to find something here, then hurry up! No one wants to stay here any longer!"
"Oh, heavens, if the Mistress knew Master Sirius brought an outsider into the Black Residence, which Kreacher serves, to steal things, how angry and disappointed she would be..."
By now, Severus had walked over to Kreacher. He observed the house-elf's extremely aged, ugly appearance and heard its impudent muttering.
"The official business we need to attend to involves this house-elf itself," Severus said calmly.
Kreacher's large eye had met Severus's gaze. It clearly didn't know who this wizard was, but that didn't stop it from transferring its resentment towards Sirius onto Severus.
However, before its spiteful words could leave its mouth, Severus had already pulled back his sleeve, revealing the Mark on his arm.
"You've seen this before, haven't you?"
Seeing the Dark Mark, Sirius's eyes showed clear disgust, but Kreacher froze. Its eyes widened even further, as if they were glass balls about to pop out of their sockets!
"The young master you served before had the same mark on him. So you recognize it."
Kreacher didn't make a sound. After regaining its senses, it stared sharply at Severus, its eyes now filled with wariness, its body pressed tightly against the wall!
"Kreacher... Kreacher knows nothing!"
"But I know some things, Kreacher," Severus said softly. "That young master of yours took something from his master. You went to that place with him and brought the thing back."
Kreacher became even more terrified. Its hands clutched at its own face-skin, and its body curled into a ball.
Sirius, standing to the side, was also stunned.
Severus looked intently at Kreacher.
"Can you bring out the thing that Regulus took you to find?"