Sirius Black always believed Kael was a rare good student.
Excellent grades, skills far surpassing his peers, and he knew how to be flexible, not confined to rigid frameworks.
More importantly, Snape disliked him... only truly good kids receive such an honor, he's certain of it.
In private, he and Lupin had discussed Kael, agreeing that if one day Kael became the headmaster of Hogwarts, they wouldn't be surprised at all.
But in just one night, Sirius overturned this thought.
Not to mention Kael's threat to beat up Harry, what kind of good student is proficient at using The Blasting Curse like that...
It has been almost half an hour; the drawing room seemed to be hosting a fireworks display, with constant popping explosions.
Moreover, amidst the Explosive Spell, there was a charm he was very familiar with.
Sirius watched as the imposing round table inexplicably split in two, the cut smooth and neat as though it was meant to be two halves.
He had seen Snape use this charm before when he was a Death Eater; they had crossed paths many times.
But he couldn't understand why Kael would know it too; surely Snape didn't teach him...
Sirius shook his head, immediately dismissing this idea. Both Harry and Lupin had mentioned Snape's dislike for Kael, and there was no doubt about that.
Sirius pondered for a long time without a clue, eventually shaking his head and giving up thinking about it.
Perhaps a book in the library documented this charm, and it just so happened that both Snape and Kael had read it.
Meanwhile, after casting spells continuously for such a long time, Kael set down his wand, panting, and sat on a chair beside him.
This box was harder than he had imagined; neither the Explosive Spell nor the Splitting Spell left any marks on it, and even Sectumsempra only made a shallow white mark.
During Kael's rest, Lupin and Sirius also tried, but to no avail.
Moreover, the explosions attracted Kreacher.
It pushed the door open, seeing the drawing room turned to ruins, eyes full of anger and fear, muttering non-stop with words like wastrel... scoundrel... brat...
Sirius felt a headache coming on and turned to shout: "Shut up!"
Kreacher obediently closed its mouth, but within a minute started mumbling again, looking at Sirius with a venomous gaze, "The master actually wants to destroy this place, oh, how sad my mistress would cry if she knew, and this wastrel even colludes with outsiders to try and open Miss Bella's..."
At this point, Kreacher abruptly stopped speaking.
But the three heard its last words sharply, all turning their heads...
"Kreacher!" Sirius immediately asked, "Do you know what this box is? You've seen it before, haven't you!"
"Kreacher does not know." The Little Elf shook its ears, sharp voice, "Kreacher will never betray Miss Bella!"
"Tell me, that's an order!" Sirius shouted.
Kreacher's expression suddenly turned hideous, but finally, it bowed low, saying: "This box was left by the old master to Miss Bella; only the ancient and noble Blake bloodline can open it!"
Blake frowned, Kreacher usually referred to his mother as mistress, and the only one called the old master would be his grandfather.
But that wasn't important anymore, he already knew how to open that box...
"Incarcerous!"
As he was thinking, a charm suddenly flew past his ear, landing on Kreacher who was about to bash the door with its head.
It was likely trying to punish itself for failing to keep a secret, but now that was impossible, it was tightly bound by a rope, unable to move.
"I order you not to inflict those stupid punishments on yourself, Kreacher." Sirius frowned.
The Little Elf stopped, but still muttered curses under its breath.
Sirius paid no heed, turning excitedly: "Haha, what were we doing before!"
Or, he cut nicked his hand with the wand, a few drops of bright red blood fell onto the box.
In the blink of an eye, the blood quickly followed the box's grain, forming bright red magic patterns.
"Click!"
With a crisp sound, the box split in two, revealing a peculiarly shaped golden key inside.
Blake immediately recognized it; it was a Gringotts Vault key, as he had one too, almost identical in appearance.
"Share half upon meeting!"
Kael swiftly grabbed the key, casually tossing the box to Sirius.
"Since this is a Blake family item, you can have it back, although it's a bit scratched, it's still usable."
"Wait..."
Sirius hadn't had a chance to speak before Kael threw the key into the chest.
"I'm not interested in the Lestrange family's vault."
Upon realizing, Sirius frowned slightly, saying: "But I must remind you, having only the key, those greedy Goblins won't let you into the vault."
"No worries, you're here, aren't you?" Kael smiled, "Once you've cleared your name, you can openly go to Gringotts as Bellatrix's cousin, relative of the Lestrange family."
"That's still not possible..." Sirius shook his head, saying: "The Lestrange family surely owns a high-ranked vault, and to make a large transfer of such vault assets, only they can do it personally, Bellatrix Lestrange, or Radolphus Lestrange.
Otherwise, you'd have to wait until they both died."
"No, I think you misunderstood." Kael said, "Those golds are secondary; I want an item in her vault."
"If it's just one item, then that's fine." Sirius said, "What do you want? Their house deeds in Diagon Alley perhaps... Let me tell you, only those are the most valuable, and any one of those is worth tens of thousands of Galleons."
"...No..." Kael used immense willpower to shake his head slightly.
"Not?"
Sirius was puzzled; he couldn't think of anything worth more than the Diagon Alley properties.
"An ancient artifact." Kael tried hard not to picture tens of thousands of Galleons stacked together, "It's hard to say now, but I think it should be in her vault."
Although Sirius didn't know what Kael wanted, seeing him say so, he nodded, without asking further.