Veritaserum.
One of the most difficult potions to brew in the Wizarding World.
Even in the British Wizarding World, there are very few Potioneers capable of producing this potion.
And due to the particular nature of this potion, similar to the Unforgivable Curses, the Ministry of Magic generally prohibits its misuse.
Every time it is used openly, it requires layer upon layer of approval, needing the signatures of multiple high-ranking officials and Wizengamot's members.
A potion with such strict production and usage conditions naturally has extraordinary effects.
Just one drop can make any staunch, unyielding hero honestly and obediently tell the truth.
Of course, if known in advance, this potion can be countered.
Someone aware they will be subjected to a Veritaserum truth test can find a trusted accomplice to use a Memory Charm on them, altering the memories they don't want others to know.
In this way, when the subject's own perception has already been altered, the Veritaserum loses its original effectiveness, and even the obtained answer is a carefully woven lie.
In the current situation, Severus naturally knew that what Sirius said was true. Using Veritaserum was simply to give Sirius direct proof in the absence of other concrete evidence.
Looking at the potion in Severus's hand, which appeared transparent but upon closer inspection revealed a faint blue hue swirling within, the gazes of everyone in the room were drawn to this vial.
"As long as you drink this, and we ask you about the things you just described again, we can prove whether you were telling the truth or lying."
Neither Lupin nor Sirius had ever seen the true appearance of Veritaserum, but it wasn't strange for a Potioneer of Severus's renown to carry a vial with him... probably?
Looking at the potion vial and hearing Severus's words, Sirius spoke first, "How do I know this isn't a poison meant to kill me!"
The tone he likely intended was sarcastic and indifferent, but the male broadcaster's voice came out as agitated and resonant, making Sirius seem more like a coward afraid of death.
In response, Severus simply shook his head.
"Do you think, given your current situation, if I wanted to kill you, I'd need to go through the trouble of disguising poison as Veritaserum?"
His voice was calm, as if anything he said carried a natural persuasiveness.
"If I truly wanted to kill you, I wouldn't have mentioned that you didn't harm Harry. I could have used that to stir up Remus and Harry's emotions, used the name of avenging Harry's parents, and finished you off directly. Why wait until now and try to trick you with a potion?"
Lupin also vouched for Severus, "He wouldn't use poison on you, I can assure you."
"Professor never uses those underhanded tricks!" Harry added.
Only Ghost Snape within Severus watched with a knowing gaze the vial of Veritaserum in Severus's hand.
This potion was indeed Veritaserum, but Ghost Snape had also witnessed what Severus had added to it earlier.
It definitely wasn't poison, but rather...
Hearing their words, Sirius was silent for a few seconds. Then he stood up and walked over to Severus.
His intensely aggressive gaze never broke contact with Severus's. Even though he was currently at a disadvantage, essentially the loser, he still carried himself with an air of superiority in front of his old rival.
So, the high and mighty Sirius opened his dog mouth towards Severus.
Severus simply smiled. He raised the small vial of potion and poured the entire contents into Sirius's mouth.
The effect of one drop of Veritaserum and a whole vial is exactly the same. Severus certainly wasn't wasteful enough to casually squander a potion worth its weight in gold.
The reason he did this was that the vial indeed contained only one drop of Veritaserum.
The effects of the Veritaserum quickly took hold on Sirius.
His originally sharp gaze gradually became empty and dazed, clearly entering the state of answering any question truthfully.
"You ask the questions."
As someone who already knew the whole truth, Severus naturally had little curiosity, so he handed the 'interrogation' rights to Lupin.
Lupin looked at the vacant-eyed Sirius, took a deep breath, and began asking about the past.
He asked every question in great detail.
Including the specific time Sirius suggested James transfer the Secret-Keeper role to Peter, how he found Peter after learning of the Potters' deaths, what kind of internal Auror interrogation he faced at the Ministry after being captured, and so on.
After Sirius truthfully recounted all the past events, not only did Lupin learn that Sirius was indeed innocent and in the clear, but Harry also learned much more about his parents' story.
After confirming everything clearly, Lupin's expression was visibly stunned.
All these years, he had never understood what exactly happened that day. Of the four who were once so close, two died, one became a Death Eater and was locked in Azkaban, leaving only him to wander the Wizarding World alone.
Of course, he had hated Sirius on countless nights, and had countless doubts, unable to fathom how Sirius could possibly be the traitor.
Until now, finally, everything was revealed!
"So..." Harry was also somewhat dazed, his breathing unconsciously growing heavier, "He really is my godfather, and he didn't betray my dad. He's been framed all along!"
Severus patted Harry on the shoulder.
"That's right. Although you can see he's a bit unreliable, he is indeed, aside from your Aunt Petunia's family, the closest relative designated by your parents in this world."
However, Harry only remained stunned for a moment before reacting again. He looked back at Sirius on the floor and couldn't help but wrinkle his nose.
That expression clearly showed he hadn't developed much fondness for the large black dog just because he learned Sirius was innocent.
Not long after, Sirius regained consciousness.
By this time, Lupin was already crouched on the floor, helping him clean off the various potion residues and glass shards.
After the man and the dog looked at each other, Lupin said with a smile,
"At a time like this, aren't you going to transform back to your human form so we can have a misunderstanding-clearing, long-lost reunion hug?"
Sirius's eyes clearly softened as well. He stood up from the floor, then paused on the spot for a long moment, as if straining every muscle but unable to, well, produce results.
Lupin still looked at him expectantly, even holding his arms out slightly, seemingly ready to give Sirius a big hug the moment he transformed back.
But the atmosphere became awkward at that moment.
No matter how much effort Sirius seemed to put in, he couldn't transform back into a human!
Immediately, the black dog's gaze turned furious towards Severus.
"What did you give me to drink!!"
Before Severus could speak, Harry spoke up discontentedly,
"What could the Professor have given you! It must be a problem with you! Why do you always think Professor is behind everything that happens to you!"
Harry's words stunned Sirius.
Initially, Sirius thought Harry's defense of Severus was because he lacked familial affection growing up, so he developed trust in this Snivellus after receiving a few small kindnesses.
And that once he himself cleared his name and proved he was qualified to be Harry's godfather, Harry would surely come around.
But reality had slapped him hard!
By now, Severus had walked over to his desk. The potion vials on it had been smashed to pieces by Sirius's crash, with very few intact ones remaining.
Among the potion bottle fragments on the floor, he searched around and soon found a piece from a larger bottle.
Ghost Snape, inside Severus's body, just stood there with his arms crossed, watching with a look of disdain as Severus put on this act.
Severus, with a completely serious face, showed Sirius the label on the glass fragment.
"This is a bottle of Potion of Invariant Essence. It's a specialized formula I obtained by chance. Its main effect is to solidify the magical state within a living creature."
The adult wizards present were no ordinary folk. Just hearing the potion's effect from Severus, they basically understood what had happened!
"You mean, Sirius accidentally crashed into that bottle of Potion of Invariant Essence, the potion spilled on him and took effect, causing the magic maintaining his Animagus form to solidify?" Lupin asked, wide-eyed.
Severus spread his hands.
"That seems to be the case based on the current situation."
Sirius, however, stared at Severus with a suspicious gaze from start to finish.
Even though his words had been rebutted by Harry, and even without any evidence, just based on intuition, he felt it was too much of a coincidence. It was most likely related to Severus.
But of course, he had no evidence now.
As for being temporarily stuck as a dog and unable to change back, Sirius was actually somewhat accepting of it.
He didn't have strong feelings about being human or dog, and the dog identity was sometimes more convenient for his actions.
It was Harry's attitude towards him that Sirius couldn't let go of.
He clearly didn't want anything else now… his only goal was to change his image and standing in Harry's eyes!
Outside the restricted area set up by the Albanian Aurors around the underground ruin in the Llogara Forest.
Barty and Perkins, dressed in explorer attire, spotted the Aurors patrolling the perimeter from a distance.
"Are you sure your information is correct?" Perkins asked.
Barty said indifferently,
"Information bought through underground channels with money, of course, can't be guaranteed to be accurate."
"What if we came all this way for nothing?"
Faced with this question, Barty just fixed his gaze on two Albanian Aurors training together.
"It won't be for nothing. These Aurors must know what all the recent commotion in this forest is about. We just need to capture one of them."
"Capture an Auror?" Perkins clearly seemed uneasy.
The large-scale Auror hunt for Death Eaters a few years back had left him somewhat sensitive towards Aurors.
Barty just laughed dismissively.
"What kind of talent do you think a small country's Auror office can attract? What kind of strict training could they have received?"
As he spoke, he already gripped his wand, seizing the moment when the two Aurors turned their backs to them.
"You take the left, I'll take the right. Stunning Spells."
The moment Barty's voice fell, Perkins, despite his earlier hesitation, displayed the experience of a seasoned dark wizard and Death Eater when it came time to act.
"Stupefy!"
Two red beams shot simultaneously from the tips of their wands.
One Auror had no reaction and was struck down on the spot. The other Auror actually knew the Shield Charm, and Barty's Stunning Spell only shattered his protection!
But before this Auror could nervously raise his wand to send up sparks, Barty cast a silent Full-Body Bind curse, instantly freezing him in place.
Seeing how easily these two were dealt with, Perkins's earlier unease instantly turned into a smug, gloating expression.
"This level is fit to be Aurors?! Any sixth-year Hogwarts student in Britain would be better than them!"
Barty, however, had no time for Perkins's pointless chatter. He went over to the two Aurors, also Stunning the Petrified one, and began performing Legilimency on them.
Silvery strands were extracted from the Aurors' minds and placed into a stone basin Barty took from his suitcase.
The memories were chaotic and disordered. To find what they wanted, they naturally had to sift through them carefully.
Fortunately, the memories Barty extracted were from the Aurors' recent experiences. Before long, they made a discovery!
"It's... it's Severus Snape!"
Seeing the scene in the Auror's memory when Severus first arrived at this restricted area, Perkins couldn't help but exclaim.
"Why is he here too?! The French are looking for him everywhere, and he quietly came to this forest!"
Barty, who had also seen Severus, now showed a cold smile on his lips.
"If he's here, that's even better."
Perkins swallowed hard and turned to look at Barty.
"Is he here to find Master too?"
Barty Jr. said coldly,
"He might be here to find Master, but it's not necessarily out of loyalty!"