How could Voldaphne possibly have known? Oleandra wondered fleetingly as Daphne's indiscriminate Descending Charm exerted its magic upon her. Flickering in and out of sight as Harry's Invisibility Cloak fluttered about her, she tumbled down from the ceiling where she'd been quietly hiding.
"Elhaz!" Oleandra managed to spit out.
Boom!
The air flew out of Oleandra's lungs as Daphne's spell slammed her down onto the cold, unyielding floor of the basement, and she spat out a mouthful of blood as her ribs cracked. Thankfully, she had managed to summon Elhaz's defensive powers before she crashed.
"Crucio!"
Oleandra rolled out of the way and vaulted to her feet, rapidly backpedalling as the crackling lightning followed her. She muttered the counter-curse under her breath, "Tinne!" as Daphne corrected her aim, shuddering as the spell finally landed, merely prickling her skin.
"The blood, we need her blood!" howled Rookwood. "Severus, your signature spell!"
Snape was already stepping forwards, silently chanting, "Sectumsempra!" as he slashed at the air with his wand. Suit the Lethifold shrieked as the shadowless blade raked across Oleandra's front, but its tough hide endured the curse quite well, shielding its mistress's vulnerable skin.
"Hang on, I'm coming to help!"
Astoria plunged her hand into her water basin on the floor. Her fingers closed around the hilt of the Sword of the Lake, and with one fluid motion she drew it forth, slicing through the bars of her cell as if through butter, then whirled to carve openings into Tracey's and Iris's adjoining cells with four swift swings.
"That cup!" Daphne snarled, spotting the golden vessel hanging at Oleandra's hip. "I knew it! I should have killed you when I had the chance!"
Something had been troubling Oleandra ever since she'd left the hospital. Daphne had known that she knew the secret of the Horcruxes, so she hadn't expected to leave Hogwarts's dungeons alive, let alone wake a month later in St Mungo's. It was obvious that someone on the inside had spirited her away for treatment… but who?
Oleandra tipped Hufflepuff's cup upside down, and a torrent of water endowed with anti-magic properties shot out. Flipping her hand, she marshalled the Thief's Downfall into forming a wall to block the incoming storm of magical bolts fired by Daphne, Snape, Nott and Rookwood.
Daphne gave a cold laugh and raised her hand. Vines burst through the gaps between the stone tiles, prising them up as they grew rapidly, thirstily gulping down the water Oleandra had conjured while stretching out like tentacles through the veil of Thief's Downfall, reaching for the cup's handle.
"The Devil's Snare!" Oleandra shouted in realisation, stuffing the Invisibility Cloak into her pouch.
Astoria became a blur as she swung her sword, hacking at the vines that forced their way forwards, but they kept multiplying and thickening. In the basement's gloom, with enough water to drink their fill, the Devil's Snare surged to occupy all available space, driving the girls back towards the cells, where Tracey was already lifting the Greengrass matriarch onto her shoulder…
"Eh?" Astoria blurted out as a sneaky vine looped around her ankle, dragging her to the ground.
Oleandra hastily commanded the Thief's Downfall to return inside Hufflepuff's cup, but it was too late; Astoria's figure had already disappeared into the mass of writhing vines.
"Tracey!" Oleandra said urgently. "We're going to need to make some light!"
"I know!" Tracey replied breathlessly.
The two girls adopted the sun rune's full-body stance.
"Sowelo!"
A spark of magic flared above their heads, swelling into an incandescent sphere whose light soon grew painfully bright. The moment the crawling vines touched the harsh light, they began to smoulder and chitter, releasing an acrid stench into the air… and before long, Daphne's command or not, they could bear the light no longer and withdrew beneath the floor.
"Sectumsempra!"
This time, Snape's aim was true.
Oleandra screamed as her left eye burst apart, a line of red‑hot pain scoring down her face as though she had been slashed with an invisible blade. Her vision swam scarlet as she stumbled back, clutching at her wound, but she couldn't staunch the bleeding…
"Oleandra!" Astoria screamed, leaping to her feet and deflecting red and green bolts of magic with her sword as they came. "We need to get out of here!"
"Take my hand!" Tracey shouted. "Everyone, grab on, quickly!"
Oleandra barely registered Astoria slipping her hand into hers, and she felt a pulling sensation as Tracey turned on herself… but nothing happened. There was an Anti-Disapparition Jinx in effect over Malfoy Manor.
"I'll do it," Oleandra gasped, almost delirious from the blood loss. "Hang on…!"
Oleandra pointed downwards, hurling the miniature sun towards the Death Eaters. Then she turned sharply, praying Tracey was still hanging onto Astoria— and in an instant, they vanished amidst a whirlwind of blue feathers.
"They've escaped…" Daphne said softly, Vanishing the small sun with a flick of the Elder Wand. "Even with the Anti‑Disapparition Jinx in place… it seems Oleandra trusted me even less than I'd imagined. She still has a fair few tricks up her sleeve she's never seen fit to mention…"
Nott crossed to the spot where the girls had vanished and bent to pick up one of the fallen feathers. "Diricawl feathers, if I'm not mistaken," he said, frowning. "This isn't the first time we've found these… it seems your sister has somehow managed to harness the innate magic of magical species… we'll have to come up with countermeasures."
Daphne turned on her heel and strode away.
"Your orders, Milady?" said Rookwood eagerly, waving his wand to coax the droplets of blood that had fallen on the floor into a phial.
"Conduct the ritual," she said coldly. "I must have a word with the Lestranges immediately."
…
Minutes later, Bellatrix Lestrange, flanked by her husband and his brother, were storming into Gringotts, killing anyone foolish enough to get in their way. Within moments, they were led to their vault, only to find it stripped bare… and Hufflepuff's cup nowhere to be seen.
The thief's calling card? A handful of blue feathers, littering the floor…