Remus Lupin was the only person in the castle, other than Sirius Black himself, who knew that Peter Pettigrew was an unregistered Rat Animagus. If Orion presented the rat to Lupin, he wouldn't need to explain the impossible; Lupin's own traumatic history would fill in the blanks.
The only missing variable was a plausible, unassailable reason for Orion Malfoy to be carrying Ronald Weasley's missing pet into the Defense Against the Dark Arts office.
"I cannot simply claim I had a hunch," Orion murmured, pacing his trunk-study while Pettigrew snored peacefully in a stasis-charmed potions jar on the desk. "And I certainly cannot say I found him. Weasley will claim I stole him, which is technically true, but politically inconvenient."
He stopped, his eyes drifting to the Monster Book of Monsters resting on a shelf.
"I need a scapegoat," Orion decided. "Or, more accurately, a scape-feline."
The Marauder's Map was useless for this specific task. While it flawlessly tracked human signatures, Animagi, and even poltergeists, it was completely blind to standard pets and animals. The parchment would be cluttered with thousands of dots if it tracked every owl, toad, and spider in the castle.
But Orion had another tool.
"Inventory," he whispered.
He withdrew the heavy brass Wayfinder Compass. He popped the lid open and focused his intent on a very specific, very ugly, bowlegged ginger cat.
Crookshanks.
The compass needle spun wildly for a second before snapping sharply to point slightly to the west. Approximately toward what he assumed the Hufflepuff common rooms would be and the kitchens.
"Sparkle," Orion said, grabbing his Invisibility Cloak. "We're going hunting."
The corridor near the Hufflepuff common room and the kitchens was quiet, smelling faintly of baking bread. Orion, completely concealed beneath the shimmering, fluid fabric of his cloak, moved silently, his eyes fixed on the compass needle.
He rounded a corner and saw his target.
Crookshanks was stalking a shadow near a wall full of portraits. The massive, flat-faced half-Kneazle looked more like a small, orange lion than a domestic pet.
Orion didn't hesitate. He moved with swift, silent precision, dropping the compass into his pocket and scooping the heavy cat up from behind, pinning its front paws gently but firmly to its sides.
"Hey! Unhand me!" a deep, surprisingly cultured voice yowled in Orion's mind, translating perfectly via the All-Speak. Crookshanks squirmed, his bottle-brush tail thrashing. "Wait, leave me! I am a creature of dignity!"
Orion pulled the Invisibility Cloak back just enough to reveal his face, looking down at the struggling ginger beast.
"Stop it," Orion commanded softly, his voice authoritative but calm. "I need to talk with you."
Crookshanks froze, his yellow eyes widening as he stared at the boy. He blinked slowly.
"Brother," Crookshanks huffed indignantly, ceasing his struggle. "You could have just asked me, you know. There was absolutely no need to pick me up like a common stray. It's terribly undignified."
"I apologize for the lack of protocol," Orion said smoothly, adjusting his grip so the cat was resting comfortably in the crook of his arm. "However, time is of the essence. I need to keep you hostage for a few minutes while I have a conversation with Professor Lupin."
Crookshanks twitched an ear. "The wolf-man? Why?"
"I am going to blame you for something," Orion explained flatly. "I am going to tell him that I found this rat"—he tapped the pocket containing the jar with Pettigrew—"and that you had killed it, or at least attacked it, and dropped it at my feet. Like a gift. It's weird, but who cares. It falls within acceptable parameters of cat behavior."
"I don't bring gifts to strangers," Crookshanks sniffed haughtily.
"And you are going to accept this blame," Orion continued, ignoring the protest. "Granted, no one but me will understand what you say if you try to deny it, but your silence and general predatory demeanor will count as corroboration."
Crookshanks narrowed his eyes, a glint of sharp, Kneazle intelligence shining through.
"Wait. The rat?" the cat asked, his mental voice dropping to a suspicious purr. "You mean the strange, balding, fat one that sleeps near the red head boy? The one missing a toe?"
Orion raised an eyebrow. "You noticed?"
"Of course I noticed. I'm smart," Crookshanks scoffed. "I knew there was a problem with that one the moment I saw it in the hands of that silly human boy. It doesn't smell like a rat. It even looks cowardly."
The cat shifted comfortably in Orion's arms, adopting a look of mercantile calculation.
"So, you want me to take the fall for hunting the fake rat. Fine. But what's in it for me? I do not work for free."
"Fish," Orion offered instantly. "I will have premium, fresh salmon delivered directly to you by a very discreet house-elf, twice a week, for the rest of the term."
Crookshanks licked his chops thoughtfully. "Make it trout on Sundays, and you have a deal."
"Done," Orion agreed. "Though I must say, you negotiate with the exact same insufferable, know-it-all tone as your owner, Granger."
Crookshanks puffed out his chest proudly. "Oh, yes. She's my sister."
Orion paused, blinking in genuine confusion. "Sister? Because she bought you?"
"No," the cat replied, looking at him as if he were incredibly dense. "Because we are kin. We share the feline spirit."
Orion stared at the cat, remembering the polyjuice incident in the bathroom. He closed his eyes, fighting a sudden, desperate urge to laugh.
"Of course," Orion muttered, shaking his head. "Family bonding via accidental trans-species mutation. How beautiful. Let's go."
Orion stowed the Invisibility Cloak back into his Inventory, and began walking towards his destination.
He didn't bother sneaking anymore. He walked openly through the corridors, drawing a few strange looks from passing Ravenclaws who wondered why the aloof Slytherin prodigy was carrying a giant orange cat. As he got closer, he removed the glass jar containing the unconscious Pettigrew, holding it casually by the lid in his right hand, while supporting the heavy, purring Crookshanks in his left arm.
He was approaching the Defense Against the Dark Arts corridor, the door to Lupin's office in sight, when the universe decided to intervene.
Orion crossed the final corner, moving with purpose.
At the exact same moment, Hermione Granger popped out from an intersecting corridor, likely going to the library for extra studies or something. She was clutching a massive stack of books to her chest, her hair flying wildly.
She saw Orion. She froze.
Her brown eyes darted from Orion's unbothered face, to the jar in his hand, and finally, to the massive ginger cat resting comfortably in his other arm.
Orion stopped walking.
Crookshanks let out a happy, rumbling trill. "Oh, look! It's my sister!"
Orion looked from the cat to the girl. The sheer, comedic absurdity of the situation was almost overwhelming.
Hermione's expression shifted rapidly from shock, to confusion, to a fierce, protective fury. She dropped her stack of books—they hit the stone floor with a resounding crash—and she whipped her wand out, pointing it directly at Orion's chest.
"Leave Crookshanks alone!" Hermione demanded, her voice trembling slightly but ringing with Gryffindor courage. "What are you doing with him, Malfoy?!"