Hidden beneath the Invisibility Cloak, Oleandra tiptoed into a shadowed corner of the Headmaster's office and unfolded the Marauder's Map. Her clone and Dumbledore's portrait were still conversing under Professor Snape's watchful gaze; neither he nor the Headmaster's painting had the faintest idea she was truly there.
There appeared to be no secret passage leading from the Headmaster's Office to the castle's nexus, as Oleandra had hoped; and if one did exist, it was not marked on the Marauder's Map. Unless she fancied combing through every nook and cranny of the office, she supposed she'd just have to go out and ask Dumbledore himself.
Oleandra levelled her wand at Professor Snape, taking careful aim. It took several tries, but at last she managed to cast a silent Stunning Spell through the Invisibility Cloak, striking the Headmaster squarely on the back of the head. She then swept off the cloak with a flourish as Snape fell over unconscious, revealing herself.
A fleeting look of surprise and anger crossed Dumbledore's aged features.
"I would very much like to know," said Professor Dumbledore quietly, though his eyes were blazing, "how you came by Harry's Invisibility Cloak."
"I didn't pick it off his cold, lifeless body, if that's what you're asking," Oleandra said coolly as she strode up to her clone's side. "Last I saw, Harry was completely fine; I nicked his Invisibility Cloak from Malfoy, but I have no idea how he got his hands on it in the first place."
The old man in the portrait directed his gaze to the two wands holstered at Oleandra's hip.
"A coincidence…?" Dumbledore said, eyes subtly narrowing. "Or do you know…?"
"That's right, old man," sneered Oleandra, seeing no reason to skirt the truth any longer. "I'm collecting the Deathly Hallows."
And as she spoke, she lifted her left hand, palm turned towards herself, revealing the black gemstone set into the ring on her middle finger. A morbid sense of pleasure stirred in Oleandra at the sight of the old man's stricken face… yet was it her imagination, or did she glimpse a flicker of sadness behind those blue eyes?
"Could it be…?" Dumbledore whispered in hushed awe. "The Resurrection Stone…?"
A complicated expression appeared on his face.
For years, he and Severus had kept careful watch over the more gifted and persuasive students of Slytherin, wary of any who might become a second Lord Voldemort. As Oleandra's powers deepened and her inner thoughts remained inscrutable, Dumbledore found himself increasingly wary of her and her mysteries… even though she had, from time to time, aided Harry in fending off Voldemort and his followers.
Dumbledore had tried to guide her on many occasions, and indeed, his efforts produced results.
When he learned that Oleandra had repelled Lord Voldemort alongside her friends, Dumbledore hinted to Scrimgeour that he should prop her up as a hero; he believed her selfish desire for fame and recognition would be satisfied by the adoration of the masses, thus turning her negative qualities into a force for good.
When Oleandra made the selfless decision to cross through the Archway and rescue Sirius for Harry's sake, without being asked to, or asking anything in return, he believed he had succeeded in making her a better person.
And yet…
How could he have failed to see that Oleandra was not a second Voldemort, but rather a second Grindelwald? A second Dumbledore, even? Her talent, her absence of hatred for Muggles and the Muggle-Born, her appreciation for the same sex, her misguided views on what made a Wizard great, her veiled ambitions, the lies upon lies… Subconsciously, he had refused to recognise their similarities, for they reflected too brightly the parts of himself he had long discarded.
And if Miss Greengrass was anything like he and Grindelwald, she was planning something big.
"I've failed you," Dumbledore said quietly.
Oleandra ignored him.
"How would you go about destroying a Horcrux?" she asked.
Dumbledore's portrait was too exhausted to exhibit any more shocked expressions.
"I suppose your sister told you?" he sighed. "I must admit, I'm rather shocked Voldemort did not seal away her ability to give away his deepest secrets…"
Oleandra said nothing. There was no point correcting him.
"The darkest curses, magical toxins potent enough to gnaw through protective enchantments," Professor Dumbledore recited. "But you need not trouble yourself over your sister's murder, Miss Greengrass. My plan is already in motion, and she need not die for Lord Voldemort to meet his end."
"The plan Harry is following doesn't seem to be going anywhere," Oleandra sniggered. "You-Know-Who, Gaunt's ring, Slytherin's locket, Hufflepuff's cup, Ravenclaw's diadem, myself, and my sister… and Harry is no closer to getting any of them."
Dumbledore's gaze flicked to the ring on Oleandra's finger.
"Haven't you noticed, Miss Greengrass?" he said. "You are no longer a Horcrux… but if you continue wearing that ring, you will be back to being one soon enough."
Indistinct voices began murmuring in Oleandra's ear, urging her not to listen, to tear the canvas to shreds and use the shattered pieces of the frame as kindling. Her eyes glazed over as her dead father appeared unbidden before her, pleading with her not to trust a dead man's lies…
"Miss Greengrass…?"
"Dumbledore's telling the truth," Oleandra muttered as she gnawed at her fingernails, drawing blood. "But I can't let go, I need all three Hallows, I need them, I need them…"
Stars exploded before Oleandra's eyes as her clone's fist crashed into her jaw, rattling her skull. She struck back instinctively, but the Reflection Doppelganger swayed effortlessly aside, wrenching her arm behind her back, knocking her legs out from under her and throwing her to the ground. The clone straddled her, wrenched the ring from her finger, and flung it away.
With each metallic peal that rang out as the ring bounced and tumbled across the stone floor, Oleandra's mind grew steadily clearer, even as her consciousness dimmed.
"The Resurrection Stone should still function even after being rid of its occupant," Dumbledore's voice echoed in Oleandra's ears. "Miss… how ought I call you? You'll find a crystal phial in the second drawer on the left, and a silver sword inlaid with rubies in the display case over there. Now, follow my instructions closely…"
Before she could hear any more, Oleandra fainted.