"What method?" Snape asked sharply.
Sean met his professor's dark gaze steadily. "Professor, you actually know this method quite well. There exists a potion that, under its influence, compels anyone who consumes it to speak only their truest thoughts and feelings."
"Veritaserum!" Hermione exclaimed.
"Veritaserum!" Lupin echoed almost simultaneously.
The two speakers glanced at each other with mutual recognition. Lupin looked at Hermione with a mixture of genuine admiration and visible regret. "It's unfortunate we're not currently in class, otherwise I would absolutely award Gryffindor ten points for such an insightful answer."
"Thank you, Professor—" Hermione began gratefully.
Before she could complete her thanks, Snape interrupted coldly. "It's equally unfortunate we're not in class, otherwise I would certainly deduct fifty points from Miss Granger for speaking out of turn without proper authorization."
That single sentence silenced Hermione completely and successfully made her eyes redden once again with barely-suppressed tears.
Glaring at Snape with renewed hatred, Sirius Black shouted furiously, "Snivellus, if I ever witness you bullying these children again, I'll—"
Snape took another deliberate step forward, his wand tip nearly touching Sirius's nose. Black immediately fell silent.
Turning back to Sean, Snape continued more reasonably, "Veritaserum can indeed resolve this situation definitively. However, I don't have any in my possession currently. Perhaps you could return to my office at the castle and retrieve some from my stores?"
"Actually, that won't be necessary, Professor." Sean smiled slightly. "I've practiced brewing Veritaserum previously for academic purposes, so I happen to have a vial with me."
As he spoke, Sean withdrew a small crystal vial of Veritaserum from his Undetectable Extension Charm bag.
Seeing that Sean actually possessed the controlled potion, Harry and his friends immediately released collective breaths of profound relief. Lupin and Sirius Black both showed faint, hopeful smiles.
Only Peter Pettigrew appeared as though he'd received news of a loved one's death. He began edging subtly toward the nearby window, already subconsciously searching for an escape route.
Observing Peter Pettigrew's movements, Sean didn't hesitate for an instant. He immediately cast a nonverbal spell, summoning a mass of thorny vines that erupted from the floorboards and bound Pettigrew firmly in place. Simultaneously, Sean addressed the trapped man directly. "If you dare attempt Animagus transformation, I will kill you immediately. Understand?"
Hearing Sean's cold threat, Peter Pettigrew immediately whimpered desperately, "Oh, Sean, Sean—you're so intelligent, you always perceive the truth! You must recognize that this entire situation was orchestrated by Sirius Black, that dangerous fugitive! He's attempting to manipulate you into using Veritaserum improperly!"
Pettigrew's voice rose with calculated panic. "That's a controlled potion the Ministry of Magic strictly forbids from private use, you understand? Once you administer that potion without authorization, you'll be expelled from Hogwarts immediately! You might even face criminal charges from the Ministry and imprisonment in Azkaban! Don't ruin your brilliant future for a worthless fugitive like Sirius Black!"
Looking down at Peter Pettigrew with cold amusement, Sean smiled thinly. "Thank you for your touching concern, Peter. However, I'm quite confident everyone present will maintain absolute secrecy about tonight's events."
Walking directly up to the bound Pettigrew, Sean held the Veritaserum vial in one hand while raising his wand with the other, pointing it directly at the trembling man. "Open your mouth, Peter. Don't force me to do this the unpleasant way."
Trembling violently, Peter Pettigrew stared up at Sean, clearly wanting to protest further. However, when he met Sean's steady gray eyes, he felt inexplicable terror wash over him. Though Pettigrew knew rationally he couldn't escape the Veritaserum, every time he encountered Sean's gaze, deep-seated fear compelled him to involuntarily obey.
Seeing Peter's mouth open in submission, Sean carefully administered three precise drops of Veritaserum onto his tongue.
At this moment, Sirius moved to step forward, clearly intending to request a dose of Veritaserum himself to prove his own innocence. However, he watched in surprise as Sean immediately stoppered the vial and returned it to his bag.
"Potions this valuable are precious resources," Sean explained calmly. "The logic is simple—if Peter is the criminal, then Black is innocent. If Peter is innocent, then Black must be the criminal. One confession resolves both questions definitively."
Everyone present basically accepted this reasonable explanation without question.
Snape, however, was different. He understood perfectly well that potion conservation wasn't Sean's genuine motivation. Snape knew his student's character thoroughly—Sean wasn't careless or imprecise in his methods. If Sean truly suspected both Sirius Black and Peter Pettigrew equally, he would have administered Veritaserum to both subjects without hesitation.
The only logical reason Sean used Veritaserum exclusively on Peter Pettigrew was that he was already absolutely certain Pettigrew was the traitor, and consequently that Sirius Black was innocent.
The critical question then became: How had Sean determined this truth before the interrogation even began?
Snape studied Sean intently, filing away his suspicions without voicing them aloud.
"Harry, come here," Sean said quietly.
Hearing Sean's summons, Harry approached somewhat mechanically. He looked at his friend with confused uncertainty. "Sean, what's wrong?"
"Of everyone present in this room, you are the most qualified person to question Peter Pettigrew directly. You should ask him."
After a moment's visible hesitation, Harry slowly nodded and turned to face Peter Pettigrew. Sirius Black clearly wasn't entirely comfortable allowing Harry to confront this painful truth so directly, but restrained by Snape's wand and Lupin's subtle head shake urging caution, he remained silent. Instead, he watched James and Lily's son—his godson—with anguished pride.
Harry stared at Peter Pettigrew, who had already entered the characteristic trance-like state induced by Veritaserum's effects. Taking a deep, steadying breath, Harry asked with surprising clarity, "Who betrayed my parents' location to Voldemort? Who sold them to their deaths?"
Peter Pettigrew's glazed eyes fixed on Harry, staring blankly. He opened his mouth, and with tremendous visible difficulty fighting against the potion's compulsion, finally answered in a broken whisper.
"It was... it was... it was me! I betrayed James and Lily! I murdered them! I sold my friends to the Dark Lord!"
With those devastating words, everything became irrefutably certain.
Sean waved his wand in a smooth arc, summoning all the scattered wands from across the dusty floor and returning them smoothly to their respective owners.
Moving to stand beside Harry once more, Sean studied his friend carefully. Harry's expression resembled the terrible calm before a catastrophic storm—as though monstrous waves were building beneath a deceptively still surface, simply awaiting the proper moment to erupt with devastating force.
Sean said nothing. At this particular moment, no words would be remotely appropriate or helpful.
So Sean simply stood beside Harry in silent solidarity, supporting his friend through presence alone.
"Harry, surrender him to me!" Sirius's voice cracked with barely-controlled rage and anguish. "I've waited twelve years for this moment! I deserve to kill that treacherous beast Peter with my own hands!"
Just as Sirius took an aggressive step forward, Snape blocked his path once again with his raised wand.
At that moment, Lupin immediately moved to Sirius's side, addressing Snape with careful diplomacy. "Severus, I believe the situation has been clarified beyond any doubt now. Sirius is demonstrably innocent. Please don't do something irreversible because of... past grievances from our school days."
Hearing this casual dismissal, Snape's eye twitched dangerously. Those relentless bullying incidents from his student years that had fundamentally shaped his entire adult life—were they merely "past grievances" worth dismissing with lighthearted words in the mouths of the perpetrators themselves?
His grip on his wand tightened perceptibly, a genuinely dangerous glint appearing in Snape's cold black eyes.
But at that precise moment, magical rope suddenly shot forth and wrapped rapidly around Lupin, binding his hands, feet, and mouth securely.
Then Sean's voice rang out clearly through the shocked silence.
"No one possesses the right to casually erase the bullying someone endured during their formative years with such dismissive words—especially not the perpetrators themselves!"