Read, enjoy, and review :)
Nagini
"He's on his way," Harry mumbled. He got up on his feet again, but was still clutching his head. "He knows I'm here."
"I'm so, so sorry," Hermione began, her voice full of regret and misery. "This is all my fault. I wanted to destroy the ring because it's been affecting everyone, and I couldn't risk anyone accidentally touching it or discovering what Horcruxes are. The bathroom seemed safe. No one was around when you left, and staying in the Room of Requirement felt too dangerous for everyone there… I just didn't want to endanger anyone." Her voice broke. "I'm so sorry—"
"It's not your fault," Harry cut off her rambling. "It's mine. I yelled in the hall - they must have heard. If I'd just…" he trailed off.
Harry's gaze wandered to the three downed men. Snape and Mulciber lay unmoving, still stunned. Avery was cowering on the floor, clutching the bleeding stump where his hand had once been. His face was twisted in agony, mouth open in a silent scream that finally broke into a series of ragged, gasping sobs.
A blinding silver light burst into the room, flooding every corner with an intense glow that chased away every shadow. Out of that radiant brilliance leapt a colossal, ethereal dog—its powerful form shimmering, paws spread wide as if it had just bounded into the room from another world. The Patronus, larger than any normal dog, scanned each person in the room. It raised its head, and from its open mouth, Sirius's voice rang out, echoing around them with an urgency that couldn't be ignored. "The Order is in the Room of Requirement!" he barked. "Voldemort's on his way to you - get out of there, now!"
It gave one last bark of warning before it faded, the silver light dissolving until only the urgency of Sirius' message lingered, leaving the room dark and quiet once more.
Astoria, still looking like Dolores Umbridge, stared at the spot where the dog had vanished, a wave of nostalgic wistfulness washing over her. She couldn't help but remember the first time she had seen that familiar form:
Daphne and Astoria had gone looking for Draco when he hadn't shown up to the Hufflepuff-Ravenclaw Quidditch match. What they had found, had been so much worse than anything they had imagined. Draco had been talking to a fugitive mass murderer, and as soon as he had seen them, he had attacked.
"Do you believe us now?" Draco had asked. It had taken a lot of explaining, but even then, the sisters had still been sceptical.
"Can you turn into a dog?" Astoria had finally asked. "I think if I see that, I might believe you."
"My pleasure," Sirius had replied, and before he had finished his sentence, he had already turned into a huge black dog.
The way the dog had looked at her, wagging his tail with playful enthusiasm, as though daring her to throw something for him to fetch… That had been enough to convince Astoria. "That is awesome. Can anyone learn how to do this?"
"Sure," Sirius had said with a casual shrug once he had turned back into his human form.
"Could you... could you teach me?"
Sirius had grinned, a mischievous spark in his eyes. "It would be my pleasure."
That had been her first encounter with Sirius and his dog form. Certainly not the last. But in this moment of chaos and terror, she longed for those simpler days. The task before them had seemed insurmountable then too, but their days had been filled with laughter and friendship, not fear and torture.
"We're done for," Ron muttered, snapping Astoria's mind back to the present. "How are we supposed to get out of here alive?"
"We hide in an empty classroom and hope that he just leaves?" Harry suggested, but he seemed to doubt that it would actually work. They all knew that if He was summoned to an empty office, he would go looking for them.
"We should wake up Snape," Hermione said. "Perhaps he can talk to You-Know-Who while we hide-"
"No!" interrupted Astoria. "No, he… we know You-Know-Who killed him. He'll do so again if we leave them alone…"
"We can't leave him here," agreed Theo. "But if we all run and leave only Mulciber and Avery here… He'll know that Snape is on our side and that we destroyed the ring."
"Not necessarily… Mione – can you cast Obliviate on them?" Ron asked, motioning his head towards Mulciber and Avery. "Like you did with your parents?"
"I- sure," she said.
"Great," Ron replied. "Then we can just leave them here. We levitate Snape out of here and hide in an empty classroom. You-Know-Who will arrive here and think someone attacked them. He'll wake them up and question them. While he does that, we sneak out of the classroom and back to the Room of Requirement."
"We can't leave Avery here – the missing hand might tip You-Know-Who off," Theo interjected. "And in any case, he might bleed to death if we leave his hand like that… I… I know we're fighting a war against them – but I don't…" His voice trailed off.
Harry's jaw tightened, his lips pressing into a thin, pale line. His eyes flickered over Avery's bloodied hand and away again, his brow furrowed deeply. For a moment, his gaze seemed distant, as though searching for answers he wasn't sure he wanted to find. Avery was unarmed, currently not dangerous, and leaving his wound untreated would lead to an unnecessary, slow, and torturous death. Eventually, he nodded, agreeing with Theo's assessment.
"It's not a great plan," Hermione said, voicing what everyone was thinking. An unconscious Mulciber might not buy them enough time to make it to safety, especially if they had to drag Snape and Avery along. "But we are running out of time, and I can't think of anything better, so let's go."
"I don't have a wand," Ron pointed out.
"Oh – just a second," Astoria said, hurrying over to the unconscious men. She knelt beside them, hesitated briefly as she looked at Snape, but then quickly averted her gaze and rummaged through Avery's pockets, pulling out several wands and handing Ron, Theo, and Hermione their wands, while she, in turn, pocketed Snape's, Avery's, and Mulciber's.
While Hermione focused on Mulciber and cast "Obliviate," Astoria took the Sword of Gryffindor, and Harry's Invisibility Cloak. Hermione repeated the process with Avery, additionally also casting a Stunner. Harry and Theo cast Levitation Charms on Avery and Snape respectively, their forms rising into the air.
Ron peeked out of the room. "The air is clear." With those words, he ducked out of the room and into a nearby classroom, holding the door open.
Theo hurried after him, muttering under his breath as he struggled to manoeuvre Snape's awkwardly dangling arms so they wouldn't hit the walls. As soon as he reached it, Ron helped him through the door.
Hermione cast a spell to muffle the noise of their hurried shuffling and whispered directions.
Harry gritted his teeth, struggling to keep Avery's body from bumping into Hermione. Avery's injured arm slipped from its position across his chest, hitting the ground with a wet thud and leaving a trail of blood.
"Hermione," Harry whispered urgently, nodding toward the arm.
She darted to his side, quickly repositioning Avery's arm. With a flick of her wand, she vanished the bloodstains.
"I hear footsteps," she whispered in alarm. She gave Harry a slight push toward the classroom.
Once the door had fallen shut behind them, Hermione spun around, raising her wand. "We should put some protective enchantments on this room." She began pacing in a wide circle around Harry, Ron, Theo, and the levitating men, murmuring incantations under her breath.
Theo pulled several vials out of his robes. "I grabbed a few potions before we left," he explained. "This one should stop the bleeding… And this one should be a Blood-Replenishing Potion."
"Should be?" Ron asked, grinning.
"I'm not a healer," Theo chuckled. He gazed around the room. Then his face fell. "Oh my god – where is Astoria?"
Astoria stood frozen in the dimly lit office, her breathing shallow and uneven as her gaze darted between the unconscious Mulciber and the door. Her heart hammered against her ribs; each beat a reminder of the seconds slipping away. The dog Patronus had given her an idea. And by Merlin was it stupid and reckless. Her stomach churned just thinking about it.
But He-Who-Must-Not-Be-Named was on his way and they were running out of time. She was certain that Mulciber would not buy them enough of it. He-Who-Must-Not-Be-Named would take one look at him and immediately hunt down whoever had dared to take out one of his followers.
Hermione had been right: Snape could distract him long enough for the rest to make it back to the Room of Requirement. But there was a problem—Snape had already been murdered once, and earlier, he'd brushed off her warnings.
"You have to stay away from the snake," Astoria had said. "You have to stay away from You-Know-Who."
Snape had only shaken his head. "Don't be ridiculous. No one is in a better position to kill the snake than I am."
He was convinced he wouldn't survive this war—and what was worse, he didn't seem to care. But she did. And Snape was certainly more valuable in this war than she was. As were Harry and his friends.
Her fingers tightened around the strand of hair she'd plucked from Snape's head earlier, when she had searched for everyone's wands. She uncorked a vial of Polyjuice Potion, dropped the hair in, and watched as the liquid turned black. Bracing herself, she took a sip.
Immediately, her insides started writhing as though she'd just swallowed live snakes. Then a burning sensation spread rapidly from her stomach to the very ends of her fingers and toes.
When she looked down a moment later, the pain had disappeared and she was no longer greeted by the sight of Umbridge's hands, but by Snape's.
A wave of her wand turned her Umbridge costume into flowing black robes. Sirius had taught Draco, Neville, Daphne, and her how to magically alter clothes when they had brainstormed how to catch Pettigrew. Draco had then used this spell to turn the Gryffindor table optically into another Slytherin table – giving her the chance to sneak into the Gryffindor dormitory to capture the rat.
Astoria exhaled sharply, forcing the memory aside. She didn't have time for nostalgia now.
Crossing the room, she opened the window and placed the Sword of Gryffindor on the desk beneath the Cloak of Invisibility. Carefully, she pocketed her wand and pulled out Snape's—or rather, Dumbledore's.
For this to work, she'd have to sell the illusion completely.
She hoped she was not making a giant mistake, for it would be her last.
Astoria squeezed her eyes shut, willing herself to ignore the knot of fear coiling in her stomach. Her knees felt weak, her body was screaming at her to run. But instead, she drew in a shaky breath, squared her shoulders, and opened her eyes.
She remembered that amongst the many potions she carried with her, there also was a Calming Draught. She quickly took a sip, then let the vial disappear again, just in time.
The door creaked open with an ominous slowness, and He-Who-Must-Not-Be-Named glided into the office. Nagini slithered at his side. As the door fell shut behind him, his crimson eyes fell on Mulciber's motionless form, narrowing with displeasure.
"My Lord," Astoria began, trying to sound as calm and collected as Snape, even though she could hear her heart racing in her ears. "I heard a commotion, but when I arrived here, I found him like this."
He paused, his expression cold and calculating, and then his voice, soft and deadly, broke the silence. "How disappointing."
The Calming Draught started to take effect, her breathing and her heartbeat calming. "I will find whoever did this, and I will make them pay, my Lord."
She stood stiffly as he began pacing, his serpentine gaze flickering between her and Nagini's coiled form. She edged closer to the table, where the hidden sword rested.
"This is Harry Potter's doing," he said, his voice a chilling murmur. "He is here. We are almost there… almost." His gaze settled on Astoria. "Skilled wizard though you are, Severus, I do not think you will make much difference now."
Astoria swallowed. She had been right - he was going to kill her. Not because Snape had made a mistake, or because he had seen through her disguise. He'd kill her just to get his hands on Dumbledore's wand. "Let me find the boy. Let me bring you Potter. I know I can find him, my Lord. I know him. I know the castle. Please."
He looked at her with cold amusement. "I have a problem, Severus," he began, his gaze wandering to his wand. "Why doesn't it work for me?"
Astoria inclined her head, trying to feign Snape's reserved confusion. "My—my Lord? I do not understand."
"I must be the one to kill Harry Potter, and I shall be. My wand failed me in the graveyard. The Elder Wand, however, will not." His eyes settled on the wand in Astoria's hands. "Perhaps you already know why, Severus," he whispered, his voice like ice. "You have been a good and faithful servant, and I regret what must happen."
"My Lord," she protested, as convincingly as she could, while subtly adjusting her stance, preparing herself. Her free hand was on the table, seemingly for support. "Whatever you ask of me is yours."
She held out the wand. When he pocketed his own wand and took Astoria's, for a brief moment, she felt hopeful. Perhaps it was enough, she thought. Perhaps he would let her live.
"The Elder Wand needs to be won in combat. While you live, Severus, it cannot truly be mine."
"My Lord!" Astoria cried, letting desperation edge her voice as she reached beneath the cloak, her fingers wrapping around the hilt of the sword.
"It cannot be any other way," he intoned. His crimson gaze turned to the coiled snake beside him.
He hissed something—sharp, commanding, and alien to Astoria's ears. Nagini reacted instantly, her coils unfurling as she slithered forward with a menacing grace. The room seemed to shrink as the snake reared up, towering over Astoria, her jaws parting to reveal glistening fangs dripping with venom.
Astoria's heart thundered in her chest, the Calming Draught no longer able to keep her fear at bay. She waited until Nagini drew back, her muscles tensing in preparation for the strike.
The snake moved forward, and in one fluid motion, Astoria pulled the Sword of Gryffindor free. With every ounce of strength she could muster, she swung the blade in a wide arc.
The sharp edge met the snake's thick neck. Blood sprayed as the severed head flew to the side, landing on the ground with a heavy thud. Nagini's body writhed violently, the enormous coils thrashing in its death throes, knocking over a chair and shattering a glass lamp.
Astoria stepped back, breathless, the sword trembling in her hands. She glanced at He-Who-Must-Not-Be-Named, whose expression was frozen in a moment of shock and fury, the severed head of his most loyal companion at his feet.
"Crucio."
Astoria's scream tore from her throat before she even hit the ground. Her entire body convulsed, seized by pain so intense it felt like her skin was being flayed from her bones. The pain tore through every nerve, every cell, with merciless precision.
As the curse was lifted, his eyes found hers. He granted her no respite. A new kind of pain erupted in her mind, sharp and invasive, as if claws were raking through her thoughts. Images surged forth against her will. She saw herself drinking Polyjuice Potion – to turn into Pansy, to turn into Umbridge, and finally, just moments ago, to turn into Snape.
He retreated from her mind, regarding her with narrowed eyes. "Not Severus," he hissed, his voice venomous. "Not the traitor I suspected—no. A child. A Greengrass." He stepped closer, towering over her crumpled form.
"Polyjuice… to masquerade as my most trusted... to infiltrate my inner circle. Clever, child, but ultimately futile. Did you think you could deceive me?" He crouched slightly, his expression twisting into something grotesque. "You thought you could steal his face, wield his wand, and live?"
"Crucio!" he spat again.
It was nothing like what she had experienced at the hands of the Carrows. Waves of agony ran through her body, each one peaking higher than the one before.
Voldemort's crimson eyes burned with a terrible satisfaction as he watched her writhe, every scream, every shudder feeding his sadistic delight.
He released her with a flick of his wand, letting her collapse to the ground like a broken marionette.
"I know your father," he hissed. "Perhaps I should… pay him a visit?"
Astoria's heart stopped for a moment, and her breath hitched, but she forced her voice to work. "N-no," she croaked.
Voldemort's lipless mouth twisted into a cruel smile, as though he savoured her desperation. "Or your sister?" he continued. "She is in the castle. I will think of you, when I kill her."
No, not Daphne. Please, not Daphne.
"You are no Severus Snape. He does not cry." Straightening, he gazed down at her, his voice dripping with malice. "What drove you to such folly? Did you think your disguise would fool me? Did you hope to spy on me?" His gaze wandered to Nagini, then the sword, then back to her, his expression impossible for her to decipher. "Did you hope to end me?" He raised his wand, aiming it at her. "Let us see, little Greengrass, what other secrets your feeble mind holds."
There was no way of keeping the memories from him. He tore through her mind with terrifying ease. Astoria focused on controlling her breathing, trying to fight the pain and fear as the most dangerous and powerful man in Great Britain rummaged through the most private corners of her mind.
A flash of her sister pulling her into a hug, then Snape severing Avery's hand came to the surface. The next moment she saw Hermione knocking out Snape with a Stunner.
She tried to redirect her thoughts—Sirius's Animagus form, that ridiculous wagging tail—but he was so omnipresent in her mind, it seemed impossible.
He pulled forth another flash of a memory: her hitting Mulciber with a Stunner, the curse that had left him sprawled and unconscious on the ground next to her.
Then – Ron destroying the ring.
He pulled back, and another relentless Crucio hit her.
"How?" he demanded. "How did you know? Who told you?" He leaned over her. "How many more have you discovered, little girl?"
Her heart was pounding in terror. She pressed her lips together, and her eyelids, struggling to summon the strength not to reveal anything more.
"Resistance is pointless." His tone was soft, but far deadlier than any shout. She clenched her fists, willing herself to focus. "The ministry belongs to me. This school belongs to me. There is but a few rebels left. It is only a matter of time now." The image of her Patronus filled her mind: the radiant, majestic owl she had conjured for the first time earlier that day. "I will rip the answers from your mind piece by piece if I must," he snarled, "and when I am done, I will destroy everyone who helped you. Your family. Your friends. There will be no one left to mourn you."
Astoria summoned every ounce of willpower she had. The owl filled her mind completely, its wings spreading wide. This was her soul. She clung to it, feeling a tingling sensation ripple through her body.
She felt herself grow lighter. She opened her eyes again. The world had changed around her, every detail had burst into astonishing clarity.
He-Who-Must-Not-Be-Named stared at her in shock as her form shifted right in front of him, feathers blooming where skin had been. He pointed his wand at her, but gravity's hold had slipped away already, and with a powerful beat of her wings, she took flight through the open window.
A scream of unbridled fury echoed behind her, followed by a flash of green light streaking toward her. But in this form, she was faster. She darted to the side, the Killing Curse missing her by a breath.
The night sky opened before her, vast and endless, as she vanished into its embrace. Behind her, Voldemort's rage reverberated, but she was beyond his reach—for now.
"We have to go back," Theo said, for what felt like the millionth time.
"We can't," replied Hermione. "It would be suicide."
"We can't let Astoria die!" Theo shot back, although his feet kept moving down the hall. They had been arguing over this ever since they had noticed her disappearance. Was she sacrificing herself for them? Did she have a plan? Should they risk going after her?
The fact that she'd taken the Sword of Gryffindor, the Cloak of Invisibility, and Snape's wand offered some reassurance, some hope that she had had a plan when she had disappeared without a word. But even with those tools, she was facing impossible odds.
Their uneasy consensus had been that she most likely had a plan, and that it would be best to retreat to the Room of Requirement. They'd patched up Avery as best they could with the potions they had, then left him Obliviated, bound, and wandless in an empty classroom. Ahead of them, Snape's still unconscious body hovered under a Levitation Spell, his robes trailing like a shadow behind him.
"Astoria is smart," replied Harry. "We have to trust that she knows what she is doing. She has the Sword of Gryffindor and the Cloak-" They were talking in circles by now.
"And no backup," Theo interrupted. "Why didn't she tell us?"
"Because we probably wouldn't have let her do whatever she is doing," Hermione mused. "She is buying us time – we have to use it wisely."
Theo's jaw clenched, his frustration evident. "We should've woken up Snape and let him deal with this. He's powerful, Voldemort trusts him—there's a hundred reasons why that would've been the better option."
"Astoria didn't want that," Hermione countered firmly. "She took his wand. Whatever plan she has—and I really hope she has one—probably relies on Snape not charging in there unarmed."
Which was exactly why they had decided against waking him up right away.
Theo knew that the others were right. But he had always felt protective of the youngest member of their group, even though she was certainly capable of looking after herself. His mind and heart were at war over leaving her behind – and he knew that the others felt the same.
"Guys – he's waking up," Ron interrupted their discussion. He lowered the Levitation Spell carefully, letting Snape settle onto the cold stone floor.
Snape stirred, groaning faintly as he tried to sit up. His eyes snapped open, sharp and assessing, darting around the group. His hands searched for his wand, but he could not find it.
"Where am I?" he demanded, his voice low and clipped. "What happened?"
They exchanged uneasy glances.
"We destroyed the Horcrux," Harry said, holding up the destroyed ring to support his words. "We obliviated Avery and Mulciber and left them behind… But Mulciber called for Voldemort… and in the chaos…" Harry gulped. "Astoria disappeared."
Snape's head snapped toward him, his eyes narrowing into an icy glare. "Come again."
"She's confronting him on her own," Theo said.
Snape rose to his full height, his dark robes sweeping around him like an extension of his fury. "Where. Is. My. Wand?" he growled, his tone dangerous.
Hermione shrank back, her voice barely above a whisper. "Astoria has it," she admitted, guilt flashing across her face.
Snape's eyes blazed with barely contained rage, and for a moment, no one dared to speak.
But then the tense silence was interrupted by a sharp tapping at the window. All heads whipped toward the sound, tension momentarily giving way to confusion. Outside the glass, an owl perched on the sill, its hazel eyes glowing in the dim light.
"A message?" asked Ron, frowning as he squinted at the bird.
"It's not carrying anything," Hermione replied. She hurried to the window and unlatched it, her wand ready in case this was a trap. The owl fluttered inside. Its wings beat the air in urgent strokes before it landed in the centre of the room, talons scraping against the stone floor. It tucked its wings tightly against its body, turning its eyes to the group with a piercing gaze.
Before anyone could say a word, the owl began to change.
Light brown feathers melted away, replaced by pale skin. The sharp curve of the beak softened and reshaped into a nose and lips, while the creature's slender frame stretched and twisted, transforming before their eyes. Limbs elongated, robes materialized, and within moments, the owl was gone. In its place stood a figure cloaked in black, their hooked nose and sharp features casting an eerily familiar shadow.
"Snape?" Ron blurted out, stumbling back as his eyes widened in shock. And indeed, there were now two Snapes standing amongst them.
"No," Theo said, his voice tight with disbelief. His eyes scanned the figure, searching for confirmation. Slowly, his stunned expression gave way to a growing grin. "Astoria?"
Astoria—still Polyjuiced to look like Snape—staggered slightly, catching her breath as she straightened up. Her dark eyes swept over her friends, taking in the stunned faces staring back at her. "Yes."
Theo rushed forward, grabbing her by the shoulders. "You—you're alive," he breathed, his voice a mix of relief and anger. "What were you thinking?"
Astoria offered a weak smile—an expression that looked almost alien on Snape's features. "I thought someone needed to kill that snake."
"You killed Nagini?" Harry asked, his voice tinged with awe.
Astoria nodded.
Snape's eyes widened; his fury seemingly tempered by shock. "You are an unregistered Animagus? And you used my wand and my face to confront the Dark Lord?"
"Sirius taught me over the last three years," she admitted, sounding almost mischievous. "At first, I did not want to tell anyone because I wasn't sure I'd be able to do it. It is difficult. And it takes time. And then it became clear that You-Know-Who would return, and I thought it would be better to not register, to keep this a secret."
Her gaze shifted to Theo. "I'm sorry I did not share my plan with you. I know it was reckless, and I knew you'd try to stop me if you'd known. But leaving Mulciber behind wasn't going to give us enough time to escape. Letting Snape face him would have gotten him killed. And we needed to kill the snake…" she trailed off. "I had the Polyjuice on me, and I knew this was our chance."
Theo shook his head, an incredulous smile tugging at his lips despite the tension. "You're completely mad," he said, his tone a strange mix of exasperation and admiration. "I demand a resorting—you clearly belong with them." He nodded toward Harry, Ron, and Hermione.
Astoria chuckled softly, her fatigue evident but her spirit unbroken. "I'll take that as a compliment."
"Are you alright?" Ron asked. "You look like you've been to hell and back."
"He wasn't exactly happy that I killed his snake," she replied. "And he cast Crucio faster than I was able to transform."
"Here," Theo handed her a vial. "This should help."
Astoria emptied the vial, some of the pain in her body easing. "You-Know-Who read my mind. I don't know how that works… if he saw more than what I saw…" She glanced at Snape.
"It is possible," he admitted.
Astoria's face fell. "He knows that we know about the Horcruxes. He knows we destroyed the ring… I don't know if he saw Sirius' Patronus..."
"We need to hurry, then," Harry said. "The snake was the last one – he is mortal, now. We have to act before he creates new ones."
They hurried the rest of the way to the Room of Requirement. They had lost the Elder Wand, the Cloak of Invisibility, and the Sword of Gryffindor to Voldemort. Voldemort knew that Harry was in the castle, and he knew they were destroying his Horcruxes.
And yet, they felt more hopeful than they had in a long time. The last Horcrux lay dead at Voldemort's feet.
Ahead of them, the door to the Room of Requirement shimmered into existence, as if it had been waiting for them all along. Inside were their friends and the Order. Together, they stood a better chance than they ever had before.
TBC
Go Astoria! When did you notice she had disappeared? Were you worried for her?
I hope Astoria being an Animagus does not feel contrived or like a Deus Ex Machina or something like that. I actually had this plan ages ago, and there are a couple of hints. The snippet Astoria remembers here is from chapter 8 if you are reading this on AO3, and from chapter 17 if you are reading this on FFN. You might remember it a bit differently – I started editing the first chapters last week. Originally it sounded as follows:
"Can you turn into a dog?" Astoria finally asked. "I think if I see that, I might believe you."
"My pleasure," said Sirius, and before he had finished his sentence, he had already half turned into a huge black dog.
Astoria looked delighted. Daphne still looked skeptical.
"That is awesome. Can you teach me how to do that, too?" Astoria asked.
"Sure," Sirius said once turned back into his human form.
It's basically the same now, just phrased a bit nicer (although I guess he now says "my pleasure" twice... I guess I'll never be completely satisfied). English is not my first language, and through writing this story, my language skills have improved so much that I wanted to edit the first chapters, so they sound similar to the later chapters. Nothing was changed regarding the plot (so you don't have to reread the first chapters), it's really only nicer phrases and correcting mistakes (like sometimes voices are horse and not hoarse and it bothers me every time, or spelling inconsistencies that bother me more than they should (Tori vs Tory)). You can recognize an edited chapter by the formatting (they now look like this chapter).
But back to the hints. In chapter 20 (AO3) / 55 (FFN), we get this moment:
Sirius whispered something into Astoria's ear, to which her eyes started to gleam, and she started to grin. He was not sure what they were talking about, but he was momentarily struck by how beautiful Astoria was when she smiled.
Okay, very obviously not edited yet – the two "started" really bother me right now, so if you are reading that particular chapter in a couple of weeks, it might be phrased a bit differently. In any case, I knew writing this that they were talking about his promise to teach her. You couldn't have known that, of course, but it at the very least shows that the two of them have interactions apart from the others, and that there is some reason to whisper.
One other I had in mind is definitely when Astoria casts her first corporeal Patronus:
Astoria's breath caught for an entirely different reason now, a soft laugh escaping her as she watched the bird. The form did not surprise her. It felt more like meeting an old friend rather than a stranger; her soul recognizing itself in the sight before her.
I know it's not much, but my thinking in writing those exact words was that she was laughing and not at all surprised because she already knew that form to be her Animagus form.
Her using Polyjuice to change her form was foreshadowing of this as well, but on a more meta level, just like the birthday prank played on the twins was foreshadowing Draco losing his memories. It made sense in my mind when I wrote those things. But maybe I'm crazy.
There're probably more instances of tiny details and phrasings hinting at Sirius and Astoria working on this, as I have always known this would happen, but I don't want to comb through every single chapter to find them right now.
I also really wanted to do the scene where Snape dies. It's been on my mind forever. I thought of Tonks doing it for a while, but it just does not make any sense, and I don't see how she would get out of there alive.
Another idea I had was of Snape killing the snake with the sword and then flying out of the window… but I don't know, that felt weird.
I am quite happy with Astoria taking over this role.
If you are wondering why Voldemort did not see through her right away – I don't think he's constantly reading everyone's mind. I think that is more of an active thing, rather than a passive ability. I know some fics do it differently, but I don't think canon shows it as always active, and it also hasn't worked like this in this story so far. Neither Dumbledore nor Snape just read Draco's mind when he was acting weird...
Anyhow, I'd love to hear what you think!