Harry began by painting a rich picture of the dog's past for the intrigued Gryffindor students. Hermione glanced up from her demanding pile of homework and, taking into account the canine's fur and physique, speculated on his breed. "He's a Siberian Husky," she deduced. "But he's unusually large.. They're already a fierce breed but this one is massive."
Despite being the initial subject of the Gryffindor's curious onslaught, Sirius reveled in the attention. It momentarily erased the sting of the haunting memories of his hunted and weary existence. Harry introduced him to the common rooms' few remaining occupants before guiding him back to the sanctuary of Sherlock Forester's office. As the sky enveloped into a dark canvas signaling the onset of the Hogwarts curfew, Sirius shifted back into his human form. Sherlock, fully engrossed in constructing quizzes for his fifth and seventh years, asked without raising his gaze, "What are your thoughts now?"
Sherlock's question punctured Sirius's temporary happiness, pulling him back into his revenge-filled reality. "Harry possesses as many friends as James and I once did. He'll manage even without me. But, Peter... Peter must pay the price!"
Sherlock took a pause from his writing, latching onto Sirius's intense gaze. "Since you've made your decision, I won't comment on it further. We can start the hunt for Peter tonight."
Under the protective veil of nightfall, Sherlock, Sirius, and Lupin ventured out from the castle. Hermione's pet, the ginger-colored Crookshanks, trailing behind. As they hovered on the precipice of the Forbidden Forest, Sirius found himself drawn to Crookshanks. "He's possibly the most intelligent cat I've ever come across. Must have some Kneazle heritage, his ability to remember Peter's scent will be of immense assistance."
Indeed, Crookshanks was peculiar, with his broad, angular face and compressed features, a far cry from conventional cats. However, there was a bizarre charm to his oddity. His trust in Lupin and Sherlock was apparent. His lack of disdain for them led the duo to follow him around at the brim of the forest. The challenging task of locating a tiny rat in the extensive wilderness was seemingly dreadful. Their reliance infallibly rested on Sirius and Crookshanks's tracking abilities.
Despite the darkness swallowing the moon, the night bore fruit. Upon discovering the familiar scent of Peter, Crookshanks led them to a location that beheld several strands of gray rat hair. It was definitive proof of Peter's hideout within the Forbidden Forest. Pressing academic commitments kept Sherlock and Lupin from dedicating their every night to this search and so in the following period the primary hunters were the dog and cat duo, assisted by Sherlock's patronus, awaiting any discoveries. The imminent end-of-term examinations loomed while Gryffindor clashed with Slytherin in the final Quidditch match. Despite their busy schedule, Sirius and Lupin stood firm on the side-lines, enraptured, as Harry led Gryffindor to their first House Cup in eight years.
Meanwhile, Sherlock engaged in an important correspondence with Hilke, who was back in Germany. She hinted at potential breakthroughs in the memory decoding process concerning the entity known as Fiddlesticks, promising the results within a few weeks to months. The antique pendant, despite its age, had now adopted a brand new sheen. It was hard to believe its historic origins when it now seemed to possess the allure of a fresh purchase. Every night, the faint rhythmic clinking sounds from the pendant's box kept Sherlock company as he attempted, albeit unsuccessfully, to remove it from his neck.
As Gryffindor celebrated the victorious Quidditch season, the dreaded examination week descended upon Hogwarts. The final few exams that were conducted by the Ministry saw Sherlock's duties lessen. He was only tasked with providing exams to the sixth years. Despite their mounting nervousness, Sherlock had faith in his students - his faith being founded on their exceptional performance in their practice tests. Even George and Fred Weasley, infamous for their pranks, had managed remarkable scores.
After supervision of the final exam, Sherlock received the awaited news of a significant lead from Sirius, still deep in the Forbidden Forest. Lupin was unavailable, leaving Sherlock and Sirius to explore the finding alone.
"He usually hides for about a week, then sneaks into Hagrid's hut to steal some food. He always had a sweet tooth, even back in school, so even if he's hidden, he won't last long without some sugar," Sirius declared, his eyes glittering with anticipation. "He was spotted stealing from Hagrid's hut near the mountains yesterday. His pattern is consistent, suggesting the next opportune moment to capture him would be the same day, next week."
Sherlock paused, deep in thought, before speaking. "Once the exams conclude, the students will anxiously await their results. After they've been issued, the holiday season commences. Lupin and I will be very busy during this period, so we should aim to capture Peter as soon as possible."
"We're unsure of Peter's plans at this point, he might try to reunite with Ron or maybe he'll continue seeking refuge in the Forbidden Forest. Thus, the opportunity you mentioned next week might be our last," suggested Sherlock, a grim understanding settling on his features.
"Starting today, I'll be on guard near Hagrid's hut, in anticipation of Peter's appearance," Sirius declared.
Murdering a nod of agreement, Sherlock allowed his Patronus to tail Sirius before making his way back to the castle. Two days later, on the evening when Harry and his fellow third-year classmates were taking their Divination exam, Sherlock found himself in the company of Lupin in his office. As they unrolled the Marauder's Map, they engaged in light conversation while keeping a keen eye on the area surrounding Hagrid's hut.
"Are you nearing your transformation again?" Sherlock enquired, casting a concerned glance towards Lupin's notably pale face. Giving a faint nod, Lupin responded, "Indeed, it should be tonight. Still awaiting the potion from Snape."
"I thought you would have reconciled by now, but it seems like your relationship seems to keep getting worse? All because of one incidence during your childhood?" Sherlock was genuinely intrigued, his eyes sparkling with curiosity. A bitter smile crossed Lupin's face, as if recalling an unpleasing memory. "Part of it was the bullying, but I suspect more significant is his obsession with Lily."
"What? How so?" asked Sherlock, an excited light of curiosity flickering in his eyes. "Did Snape know Harry's mother?"
"Precisely, Snape and Lily were childhood friends, although he obviously wanted to be more than that. However, Lily chose James, Snape's nemesis throughout their school years. This left him deeply resentful. He despised James and the rest of us. At some point, there might have even been resentment towards Lily too."
"That would also explain his ill temperament towards Harry, no?"
"Exactly. Snape is, in fact, transferring his hatred for James onto Harry," Lupin's voice was barely above a whisper. "But somewhere, he still has remnants of affection for Lily. So, he abhors Harry, and yet doesn't want him to come to harm."
"Tsk tsk, what a complex sentiment!" noted Sherlock. Right at that instant, Lupin frowned in confusion, his ears slightly twitching. "Did you hear that?"
Sherlock replied with equal confusion, "No, I didn't hear anything."
Lupin stood and strained himself, trying to locate the source of the noise. "Like the ticking of a clock..."
However, he was interrupted by Sherlock's sudden alertness. "My Patronus Charm has been cancelled!"
Lupin, who had been fervently straining to catch the vague noise, went stiff. Both men directed their attention towards the Marauder's Map, eyes darting to Hagrid's hut. Among the names of Hagrid, Harry, Ron, and Hermione, a noticeable name was glaring back at them - Peter Pettigrew! Sherlock and Lupin had no time to ponder over the previously mysterious sound; they rushed out of the office towards Hagrid's hut.
Simultaneously inside Hagrid's hut, the atmosphere was grim. Buckbeak's execution day had finally arrived. Harry and his friends, fresh from their Divination exam, had congregated at Hagrid's, sneaking out under their Invisibility Cloak, to comfort their friend. Emotions hung heavy in the air, they all voiced their opinions against the unjustified punishment given to the innocent creature Buckbeak by the Ministry of Magic. Hermione was reduced to silent tears. As she tried to pour milk into a jug, a rat unexpectedly fell out startling her!
Ron, looking rather confused, picked up the squeaking rodent. "Scabbers! What are you doing here?"
Hagrid, looking stern, bobbed them towards the door. "Please, leave quickly! The executioner will be here any minute, it's far too grim for you to witness. Not to mention if you're found sneaking out, the punishments would be severe."
Harry and his friends donned the Invisibility Cloak and started the eerie walk towards the castle. Ron's pocket bumped and thumped continuously by a desperate Scabbers. Still, in a moment of unnoticing, Scabbers finally managed to slip out. But as he darted towards the Forbidden Forest, a ginger feline, Crookshanks, pounced and snatched the desperate rat.
"Curse you, Crookshanks! I knew he was behind this all along!" Ron cried out, pursuing the cat into the night.
"Ron, no!" Hermione called out helplessly, exchanging a quick glance with Harry before bolting after their friend. The path Crookshanks had carved was rather definite, leading them deeper into the Forbidden Forest. Catching up to Crookshanks, Ron snatched Scabbers from the feline's clutches. Rejoice was short-lived as they an enormous, grim-looking canine blocked their path back to the castle. Harry immediately recognized the dog. "It's that dog! It's Professor Forester's dog!"
Hermione, pleading with the creature, begged, "Please, be a good boy, move! Here! Fetch!" she shouted as she threw a stick for the dog to chase, but Sirius, instead of moving, glared at them with an unyielding stare. Having found his courage, Harry reached for his wand. But before he could take action, they heard the crunching of twigs and the rustle of leaves.
Spotting their rescuers, Harry called out. "Professor Lupin!" Following Lupin was none other than Sherlock. However, Harry was soon stunned into silence. Instead of acknowledging their greetings, Sherlock and Lupin, severely expressioned and wands in hand, stood their ground. Sirius, no longer in his dog form and donning a wand borrowed from Sherlock, pointed his own wand, not at Harry, but at Scabbers clenched in Ron's hand. Harry, wide-eyed with disbelief, glanced around at the alarming sight. "Professors, how could you...?"