The professors still hadn't found any trace of Sirius Black inside Hogwarts Castle. When Sean heard the news, he wasn't the least bit surprised. Of course they hadn't found anything — while the staff were scouring the castle's hidden passages and empty classrooms, Sirius had already slipped through a secret tunnel and vanished into the Forbidden Forest. If they'd actually caught him, that would have been a surprise.
As for Sirius, Sean had no intention of wasting effort on him for now. It wasn't that he didn't want to — it was just that the Forbidden Forest was enormous, wild, and unfamiliar. Even if he did go poking around, he'd only risk spooking Sirius deeper into hiding. It was pointless to hunt blindly when the real prey was still right under his nose.
So for now, he would bide his time.
Over the next few days, Hogwarts buzzed with rumors about Sirius Black. With each retelling, the rumors grew wilder. By the time they made their way to Sean's ears, Sirius Black could supposedly transform into a flowering bush, slip between paintings like a ghost, become anyone he wanted to dodge the Dementors, or turn into an animal to sneak past Hogwarts' defenses.
Sean couldn't help but shake his head when he overheard the students whispering in the corridors. Among all the ridiculous gossip, there were fragments of truth hidden like splinters in hay — but the students were too busy fueling their own fear to see it.
It didn't matter. Sooner or later, Peter Pettigrew would slip up, and then Sirius wouldn't need to hide anymore.
For now, Sirius Black's name still dominated every conversation — until the approaching Quidditch season began to reclaim Hogwarts' attention. The excitement spread like fire through the common rooms. Badges were pinned to robes. Banners appeared overnight. And the students' nerves turned from talk of murderers to the next big match.
Sean hadn't forgotten what usually happened during Quidditch season. The roaring crowds, the rush of adrenaline — it was like laying out a feast for Dementors starved of happiness. He vaguely recalled that in the original timeline, the Dementors had swept down over the pitch, drawn by the collective joy, and Dumbledore had intervened in time to keep disaster at bay.
But this wasn't exactly the same Hogwarts he remembered from before. Things had shifted — some small, some large — since he arrived here. He couldn't guarantee that events would play out the same way again.
Of course, he could simply skip the match altogether. If he wasn't in the stands, there'd be nothing to worry about.
But that wasn't really his style — and besides, it wasn't the sort of world where you could just hide and hope nothing came for you.
So with the Quidditch season gradually approaching, Sean Bulstrode stepped up his progress in learning the Patronus Charm with Lupin.
"Sean, because we can't catch real Dementors to practice on, I've decided we'll use a Boggart instead," Lupin explained. "So now the only problem is that what you and I fear most isn't Dementors. Can you tell me — what should we do now?"
Hearing Lupin's question, Sean answered at once: "You can use the Confundus Charm, Professor."
"Very good answer. So, are you ready, Sean?"
"Of course, Professor."
"Then, let's begin!"
As Lupin spoke, he swung open the old wardrobe. The Boggart floated out in the shape of a silvery moon. Lupin raised his wand and pointed it at it.
"Confundus!"
A swirling, muddled light of shifting colors struck the Boggart. Bubbles rose and shifted across its form like boiling liquid — expanding, shrinking, churning without bursting.
This transformation lasted about ten seconds. Finally, facing Sean and Lupin, it morphed into a creature cloaked in tattered black robes. Its entire body looked blistered and rotten beneath the rags, its pallid, scabbed hands dangling like a corpse's. Beneath its hood, no face — only a gaping, hollow mouth.
A Dementor!
Strangely enough, even a Boggart-turned-Dementor could truly drain happy thoughts.
Sean stared at the false Dementor drifting closer, feeling a creeping cold pierce him. Buried grief flooded back — a memory not of this life, but of a man with an unfamiliar, gaunt face. He lay dying in a stark hospital bed, alone and voiceless. No family, no visitors, only a bored nurse eating fruit, playing with her phone, pretending to care whenever a doctor passed by. He had once wanted water — but could not even ask for it.
Sean's eyes unfocused, lost in the memory of a life that hardly felt like his own.
"Sean! Recall your happiest memory — don't sink into the grief! Hold onto something happy!"
Lupin's voice echoed through the chill like a rope thrown across a dark gulf.
Sean drew in a shuddering breath and dragged his mind back. He thought of Adrian and Margaret waiting for him at home; Aldrich and Jason at his side; Blaise and Andy laughing with him; little Caesar, soft and warm, stretching out tiny hands for him.
"Expecto Patronum!"
Buzz…
A shimmering mist of silver-white poured from Sean's wand, spreading like a gleaming shield that pushed the Boggart-Dementor back.
"Adjust your memory, Sean — real or imagined! Make your Patronus take form! Only a true Patronus can drive a real Dementor away!"
The false Dementor lunged against the fragile silver barrier, clawing at it — but Sean stood firm, wand raised, breathing steady.
According to Lupin's instructions, Sean Bulstrode kept adjusting his memories. He summoned every moment of warmth and joy he could find, drawing those feelings out from the depths of his heart — letting them turn into pure positive magic and pour into the Patronus Charm he cast.
In the silver-white mist of the Patronus, a faint, slender shape began to form. The instant that ghostly silhouette appeared, it lunged straight at the Boggart-turned-Dementor and smashed it backward — driving it straight back into the old wardrobe.
The false Dementor was defeated. The moment the threat vanished, Sean's Patronus broke apart and faded.
Lupin looked at Sean — at the boy who, after less than a month of training, with only two short sessions each week, had already conjured a faint but genuine Patronus. For Lupin, this was astonishing — a level of talent and willpower he had hardly ever seen.
Lupin was stunned.
And Sean was no less surprised.
The moment the Boggart-turned-Dementor was forced back, Sean's panel immediately flashed with a new prompt. He checked it at once — just as he expected, it confirmed that he'd gained an ability by defeating the Boggart.
When he'd faced the Boggart in class before, the panel had remained silent. Back then, he had assumed that a Boggart wouldn't trigger the duel mechanism at all. But now it was obvious: that earlier classroom scene hadn't counted as a real duel in the panel's eyes. This time, however — facing down the Boggart in its Dementor form — the panel recognized the victory.
And so, Sean had gained the Boggart's ability.