It seemed unfair to consider the Riddle House overgrown when the Gaunt shack looked as it did; little of the shack was actually visible. There were dead and dying trees growing all over the block, like a forest had tried—and successfully managed—to reclaim the land. Through the gaps in the trunks, the shack itself was so covered in moss, lichen, and weeds that the place could have been mistaken for a hill rather than a house. The walls were covered in creeping vines, and patches of mould covered what stone was left, and most of the grimy windows.

It smelled like decay, but in an unnatural sort of way that made Sirius want to gag.

"Merlin," Dora muttered, beside him, and then stiffened and, with more urgency, said, "Oh, no—"

Morfin Gaunt lay in a dilapidated chair on the porch. He was skeletally thin, and filthy, though he couldn't have been dead long—the body looked relatively whole, and the smell of rotting flesh was mercifully absent—

Gaunt stirred as they neared the gate, and it was then Sirius realised he wasn't dead at all.

"Oh," Dora said, eyebrows shooting up in something halfway between relief and horror. "Hello, Mr Gaunt—"

"Heh," the old man said, in a creaking voice. He had to be at least ninety. "Mr. There in't no Mr 'ere—" Sirius wasn't sure what Gaunt called Dora, since he hissed it more than he spoke it, but Sirius was sure it wasn't anything nice.

"I'm Auror Black—"

"I know you," Gaunt slurred, shifting in his chair. There were no rings on his clawed hands, which was both a relief and disappointing. "Sir's Black. Was a fan o' yours, 'til they realised y'adn't done it." He spat onto the slimy porch. "Your sires'd be rolling in their graves if they could see you now. Muggle lover. Blood traitor—"

"That's enough, Mr Gaunt," Dora said firmly. "We're Aurors, with the Ministry." Gaunt spat again, conveying quite clearly what he thought of that. "We've come to see how you're doing." Gaunt seemed to ignore her. Dora took a breath and tried again, tone as sunny as she could make it; Sirius could smell the effort, though it didn't show on her face. "Can we come in and have a chat?"

Gaunt hissed something at her and chuckled to himself.

"Here, then?" Dora murmured. "If we can't get inside? Should be enough to tell us if there's anything in the vicinity—"

"Do it," Sirius murmured. He stepped forward to lean on the gate, and also to block Dora from view; he wasn't sure how Gaunt would react to them performing magic around him and his property, but he doubted it would be positive. "Your nephew's causing quite a stir out there," he said more loudly, and Gaunt snarled at him, amusement gone. "Seen him lately?" Sirius continued. He heard Dora start to murmur detection charms, and suspected she was doing it purely for his benefit, so he'd know how much more time she needed. "He was living up at his dad's place for a while—"

"No nephew o' mine," Gaunt said. His lip curled, showing missing teeth. Those that remained were broken or yellow, or both. "Little—" He hissed something and it was such a poisonous sound there could be no mistaking it for anything affectionate. "Best parts o' him came from this line, from my father, and how does he r'pay it? Has me sent away. Kills his filthy father—'n that part I can understand—but then he puts it on me. Steals from me—took m'father's ring, damned thief, just like his wretch of a mother—ran off with our locket when she went, she did."

"So you've not seen the ring since?" Sirius asked. Dora sucked in a breath behind him—perhaps because he was not being at all subtle; he had a feeling subtlety would be lost on the likes of Gaunt. Her scent wasn't exasperated or amused, though; it was grim, and a little wary. "Not found it since you were let out…?"

"It's gone," Gaunt snarled.

"It's not," Dora breathed. "Or— maybe it is, but there's something here. Something wrong." Sirius did not look back at her, lest he make Gaunt suspicious, but he hummed softly to let Dora know he'd heard.

Ostendere me omnia, he thought, and couldn't help but take a step back; the Gaunt shack's garden was distinctly unmagical, Gaunt himself was a steely green-grey, but faded—Sirius suspected his time in Azkaban was to blame—and the house itself…

The house had no proper wards on it—nothing defensive, or protective—but thin lines of magic—meant to do Merlin-only-knew-what—clung to the walls. There was a swirl of silver, green and black magic on the door, tethered to several of those, and beneath the floor—either in a formal basement-type structure, or in a naturally formed cavity beneath the floor—was a mass of inky blackness. It was wrapped in thick nets of silver, black and green magic that took Sirius right back to the cave where they'd found the locket.

His stomach turned even as his heart leapt; they'd found one.

Sirius did turn properly to Dora now, though he kept his voice too low for the old man to have a hope of hearing:

"That's a horcrux," he said, "or I'm no muggle-loving blood traitor." Dora smiled weakly, but her eyes were sharp and still fixed beyond him. She led him a little way down the road, out of Gaunt's sight and earshot.

"We'll have to get Gaunt out of here," she said. "I don't want civilians around if it acts up when we try to take it." She frowned. "And I do mean try; it's hideously well protected. It'll be under the floor, since that's where it's thickest, but even the walls… some sort of trap, do you think?"

"Probably," Sirius said. "Dumbledore might have some ideas… he said to let him know if we found one." Dora glanced around and he was sure she was checking whether they had enough cover—from Gaunt or from the not-so-distant muggle village—to send a patronus.

"Send it," she said, nodding. She smiled a little nervously. "I'd feel better tackling this with him here." Sirius didn't say so aloud, but even if Dumbledore couldn't get away from Hogwarts to come and join them, Sirius would feel better just knowing that the Headmaster knew where they were and what they were about to attempt. "And while you do that, I'll let Remus know too."

"Good idea." Sirius reached for the pocket which usually held his mirror, though he hadn't carried it for a few weeks; Harry's was still with Umbridge. Lately he'd been carrying the parchment Harry'd given him, and a fountain pen—much more portable than a quill and inkwell, and a far better writing implement than those silly, plastic pens muggles used.

Kiddo, he wrote, leaning on the dilapidated fence, then paused. He tapped the pen against the wood, thinking. Dora and I finally had a chance for a proper look today and think we've found that ring we've been looking for—you know, the one that Reg was on about when we first moved in? Sirius paused, deliberating over If anything happens, and Try not to worry, only to settle on, In for a busy afternoon, I think. Will check in again later, once everything's settled. Love you.

He watched the ink fade into the parchment, then lifted his wand and conjured his patronus.

"I've got a message for Dumbledore…"

"We've found something," the large, silvery dog announced, with Sirius' voice, "at his uncle's place."

Doubtless, Sirius had been deliberately vague in case Albus was not alone when the patronus reached him; his first thought was that 'uncle' referred to Vernon Dursley—Harry's uncle—but that didn't make sense at all…

Albus understood a moment later.

Sirius was not supposed to be in Little Hangleton—they had agreed at the last meeting not to bother—but a little thing like not supposed to had never stopped Sirius… or Nymphadora, for that matter, who Albus suspected was the other half of the 'we' Sirius had referred to; Remus would not have risked leaving the safety of Grimmauld Place.

Albus stared at the spot where the patronus had disappeared, even as he held his arm out to Fawkes, and lifted his wand.

Two silvery replicas of the very phoenix that has just alighted on his arm bloomed from its tip:

"Is it safe to join you?" he asked the first. It vanished with a trill.

"We shall have to delay our meeting," he told the other. He checked his watch. "I should be free after dinner."

They had no meeting scheduled; the message was a code he and Minerva had devised shortly after Dolores' arrival. It meant Albus was unavailable—likely off the grounds—and hoped to be back by the time he'd specified. In the meantime, Minerva could notify Severus—and anyone else she deemed necessary—and make his excuses to the rest.

The phoenix soared through the wall, just as Sirius' patronus reappeared and barked, "Yes."

"Excellent. To Sirius Black," Albus told Fawkes, and let his office vanish in a swirl of warm, musical fire.

He and Fawkes materialised on the dusty, gravel road beside the Gaunt family's home. Morfin Gaunt startled to his feet on the porch, wand drawn, but stilled at the sight of Albus and Fawkes. He did not look significantly worse than when Albus had last seen him, but he did not look much better either. Life outside of Azkaban was clearly not much kinder to him than life inside it had been. Albus wondered if it was the result of living in such close proximity to a horcrux that was the cause, but tentatively dismissed that; Harry had lived with one for almost fifteen years, and both he and Sirius had lived with the locket at Grimmauld Place for a number of years too.

Nymphadora lifted a hand in greeting, and Sirius—leaning against the gate with his eyes on Morfin—nodded in Albus' general direction.

"It's here?" Albus asked, as he approached them.

"Under the floor," Sirius said, even as Albus' own murmured charms let him see the magic beneath the house, glittering in dark, intricate coils. "What do you want to do with him?" Sirius jerked his head toward Morfin, who had not moved to sit again, and was eyeing the three of them mistrustfully.

"Allow me," Albus said, stepping forward. "Morfin—"

"I remember you," he said, and Albus was honestly a little surprised that he did. Azkaban had not been kind to Morfin Gaunt, and it had been several years since they'd last spoken. "Dumbledore." He hissed something, lip curling. "Tracked me down, have you?" He said this as if it must have been a challenge, as if he had made some attempt to hide, and not simply returned to the house he'd lived in before his incarceration.

"So it would seem," Albus said, with some amusement.

"What d'you—"

But Albus gave his wand an inconspicuous wave and Morfin slumped sideways with a sudden snore. Albus pulled a blank chocolate frog card from the pocket of his robes and tossed it into the garden. It landed beside one of Morfin's filthy boots and when he fell, it was not to the hard ground, but into the empty frame.

Albus summoned the card back and studied Morfin's sleeping portrait with satisfaction.

"That's wicked," Nymphadora said, peering over Albus' shoulder. "Can he stay there long?"

"A few days at most," Albus said. "Though with luck we'll free him sooner."

"I'd hope so," Nymphadora said. "Surely we can just do what we need to do here and then let him out again—"

"For Voldemort to find?" Sirius asked.

"Voldemort's got no reason to know we've been here," she said. "And this is Gaunt's home. Where else is he going to go?"

"That is a conversation for after we have the horcrux in our possession, I think," Albus said. He offered the card to Fawkes, who curled his scaly foot around it. "For now, he can go to Minerva."

"To…?" Sirius frowned at Albus. "But—"

"Should something happen to us here," Albus said, "I would not have Morfin caught in the crossfire and entirely unable to defend himself. Minerva will be able to free him, should something happen to stop me from doing it myself."

"Cheerful," Sirius snorted.

"It's transfiguration, then?" Nymphadora asked, nodding at the card.

"Predominantly," Albus said, inclining his head. He pushed the gate open and stepped into the Gaunts' garden, Sirius and Nymphadora on his heels.

They scouted the garden while Albus transfigured leaves and sticks into parchment and a muggle pencil and wrote a short note to accompany the card; Let Harry and Remus know if I miss our catch up. Both Harry and Remus would recognise Morfin's name—if not his face, from the memories Albus had provided—and Remus would, presumably, know that Sirius and Nymphadora had been out following leads on horcruxes. Between them, he and Harry would be able to piece together a clear enough sequence of events to arrange a rescue or retrieval mission in the event that something went horribly wrong.

Fawkes disappeared in a flash, clutching both the note and Morfin's card, and Nymphadora and Sirius returned.

"Garden's all clear," Nymphadora said. Sirius nodded an affirmative and on an unspoken cue, all three of them turned to look at the house.

"Reckon we can just walk in?" Sirius asked. "Gaunt's obviously been coming and going without any issues."

"We can try," Nymphadora said, though she glanced at Albus for confirmation. He inclined his head.

They reached their first hurdle at the front door.

The skeleton of a snake was nailed to the old wood with a rusty nail, and as Sirius—who'd taken the lead—reached for the handle, the snake stirred and hissed at him.

Sirius withdrew his hand at once, and Nymphadora stepped back and raised her wand, but the snake made no move to attack. It swayed, surveying each of them through empty eye-sockets.

"A gatekeeper, I think," Albus said, studying it. "Voldemort did not place it here—" He remembered the snake, though far more freshly dead, from Bob Ogden's memories. "—but that does not mean he has not given it additional purpose..." He curled his wand over the door and was unsurprised to see Tom's magic woven through the snake's bones. "Yes." And tethered to it were multiple lines of magic, magic which wove into the walls and floor. He let the spell go. "The real question is whether it is the trigger for whatever nasty effect Tom has left for unwelcome visitors, or whether it is the thing that will be triggered."

"I'm going to guess it's the thing that sets off all the rest," Sirius said, eyes roving the house's walls and floor. "So we need to figure out how to get past it the proper way—however Voldemort would do it, if he was visiting."

"We could try to disenchant it?" Nymphadora said.

"That is an option, but likely unnecessary," Albus said. "Morfin appears to have managed these last few years, after all. A password seems more likely."

"Or an offering," Sirius said, frowning at the snake. "The cave needed blood."

"I doubt Morfin's been bleeding every time he goes inside," Nymphadora pointed out. "It could be to do with parseltongue, maybe?"

"Probably," Sirius agreed, and Albus inclined his head, having reached the same conclusion. Sirius glanced at Albus. "What's the likelihood of Morfin guessing one of Voldemort's passwords?"

"Low, I think," Albus said. "But not impossible, especially if it is related to the family." Sirius scowled at the snake. "I suspect, however, that the ability to speak it at all, may be enough." Or at least, he hoped so.

He cleared his throat and hissed.

The snake cocked its head, then drooped back against the door.

"You speak parseltongue, sir?" Nymphadora asked.

"I have a rather good memory—good enough to hear a phrase used and repeat it… in this case, something Morfin Gaunt said in Bob Ogden's memory," Albus said, with a small smile. "I couldn't tell you what I just said, though, and if the snake wanted to continue the conversation, I would be quite useless." The door clicked open. "Happily, this seems to have done the trick."

Sirius snorted quietly, straightened, and gave the door a gentle push. It swung open with a loud groan.

It was dark inside—what daylight could make it through the thick trees around the house could not filter through the grimy windows and mouldy curtains. In fact, the most prevalent source of light was what was trickling through the gaps in the roof, where tiles ought to have been.

The whole place smelled damp, like mould, rot, and old food. Albus wrinkled his nose and felt very sorry for Sirius, who coughed and scrunched his face up.

"Loculumen," Nymphadora murmured, and several balls of soft yellow light bloomed from her wand tip and sped inside, lighting the corners of the room. "I think taking Gaunt away from here is a kindness," she said in a hushed voice. "Look at this place! Mum wouldn't have said a word about my room growing up if she had this to compare it to."

The pots and pans in the kitchen were rusted, and there wasn't a plate, bowl, or mug in sight that wasn't cracked or chipped; he could see that because the cupboards were exposed by a door hanging off its hinges. Moss and dead leaves littered the floor, which was remarkably intact, and vines crawled over all but one part of the filthy couches; presumably, Morfin sat in that particular place regularly enough that nothing grew there.

Spiders had made homes in the corners of the rooms, and in most of the other nooks and crannies about the place, except the ones which had been claimed by mice.

The only thing in the room which wasn't old, broken, or dead, were a cluster of potatoes, carrots, and beans resting on the kitchen bench.

"S'pose he had to be eating something," Sirius said, nudging the closest carrot with his wand. It rolled limply onto its side. "Must be a garden somewhere out there." He cast a dubious look back through the door.

"It's definitely under us," Nymphadora said, squinting down at the floorboards. "There's nothing in either of those, other than the bits of magic on the walls." She nodded at the cottage's other rooms; through their ajar doors, Albus could see a bedroom and a bathroom.

"Just need a way down," Sirius said. "One that isn't going to blow this place up."

"There," Nymphadora said, pointing over to the fireplace, which was almost overflowing with ashes and lumps of charcoal.

Albus moved his wand in the same curling motion he'd used earlier. From above, the magic beneath the floorboards gleamed here and there with silver or green, but was mostly black and as thick and endless as a void, though Albus had seen from outside the house that it was only a storey or so deep. He refocused; on the other side of the room, where Nymphadora was pointing, was a faint, silver-green… something.

Sirius was the first to move, stepping gingerly, though more, Albus thought, to avoid the detritus covering the floor than out of fear; dirty boot prints and patches that broke up the dust showed Morfin had been able to move around freely enough.

"It's a rune," Sirius said, and when Albus drew close enough he could see for himself. It was a sharp shape—all corners and angles rather than curves or swirls—and both nigglingly familiar, and entirely foreign. "I'm no good with—"

"It would not help even if you were." Albus crouched, tucking his beard into his lap so it didn't trail over the floor. He vanished the mountain of ash and charcoal, but the fireplace held no other clues, magical or physical. Albus sighed and traced the shimmering magic with a hand. "This is one of Voldemort's runes, one that he has devised himself."

"The ones Bill and the kids have been working on?" Sirius asked. "Like in the Mark?"

"The very same," Albus said. "I recognise part of it, I think" He brushed a finger through the central part of it, which resembled a pointy, misshapen S, with embellished ends. "Fire, I think, or perhaps heat?" But that was assuming the other strokes branching off the rune's main stem didn't change its meaning entirely…

"Makes sense," Nymphadora said. "It's on a fireplace."

"Indeed," Albus murmured, frowning at the gleaming lines.

"So, water, then?" Sirius asked. "Because to deal with runes you use their reverse? It's… er… mer-thing."

"Merkstave," Nymphadora said absently. "But… no… if you look at the way this one's drawn, it's pulling in…"

"Ah," Albus said, looking more closely. She was right; the outer edge of the rune appeared to be rolling back in on itself, rather than simply projecting itself or even sitting statically. "A recipient rune." He smiled at the look on Sirius' face. "Recipient runes take—usually the spell, substance, or cost dictated by the rune itself, but occasionally its opposite. Other runes—donor runes, which is what you were talking about—are those which must be countered, usually with a merkstave."

"Right," Sirius said. "So if we light a fire in the fireplace…?"

"Then we shall likely fare better than if we were to try something with water, but I do not think it will be so simple…" An idea occurred to Albus, and he traced a hand over its shape. "I wonder…"

"Wonder what?" Sirius asked.

"Remind me again what defences were in place in the cave," he murmured.

"Blood to get inside," Sirius said, frowning. "Inferi in the water, and then there was the Dementor's Draught." His expression twisted.

"And the diary was protected by Lucius—by the reputation and family home of a pureblood," Albus murmured.

"The diary could protect itself, too," Sirius said. "And there was the fact that unless you knew who Tom Riddle was, it wouldn't mean much to anyone…"

"Indeed," Albus murmured. "The same is true of our location, I believe—unless you had successfully identified Voldemort's maternal line, this cottage would be of no significance… The snake at the door provides certainty—or, at least, I am certain Voldemort thinks so—that no one without the gift of parseltongue can enter… but if they could, if they had…" He would want them stopped, challenged, Albus was sure of that.

"I can think of two possibilities," he said. "The first is a protective curse—Protego diabolica." Both looked blank. "It summons black fire designed to eliminate its caster's enemies, while leaving their allies intact." Sirius' mouth twisted. "The other possibility is Fiendfyre."

Nymphadora's hair darkened and her face paled. Sirius looked troubled.

"And you think they're possibilities because they're both cursed fire?" Nymphadora asked. Albus inclined his head:

"It would explain the additions to the rune," he said. "Of course, it could be something else entirely—"

"But you don't think so," Sirius said shrewdly.

"No," Albus said. "It's a fireplace, and Tom was always very literal. I think there's a good chance one or the other is our solution."

"Regardless, it's a trap," Sirius said. "If that's a receiving—sorry, recipient—rune, then we'd have to give it Fiendfyre to deal with it. It's just as likely to take us down and the shack with us." Nymphadora looked rather ill. "And the other one, the diabolica curse… I've got a feeling that we're just as likely to unleash a version of it, targeted at Voldemort's enemies—"

"That's the answer, then, isn't it," Nymphadora said, and her voice shook a little.

"Quite," Albus agreed. "The rune wishes to receive, and so, of the two, the Fiendfyre is far more likely—it is the only one we can give."

Sirius looked at Nymphadora, then reached out to squeeze her shoulder; she leaned into the touch. Albus wondered if that night in the forest at the end of Harry's third year had stuck with her these past few years; she looked worried but composed, so something else must have prompted Sirius' response—her scent, perhaps, or her heartbeat.

"Except Fiendfyre can destroy horcruxes," Sirius said. "Harry and I read about that, years ago, when we were trying to figure out what a horcrux was. Some Ancient Roman emperor died because his horcrux's hiding place burned down."

"So maybe he's protected against that?" Nymphadora said, biting her lip. She frowned and glanced at Albus. "Can you protect against Fiendfyre? Mad-Eye and I were able to hold it off for a bit, and so were you, but we couldn't put it out…" Her eyes had a faraway look in them.

"I'm certain he has devised a way to protect against it," Albus said; if Sirius knew that was a way to destroy a horcrux, Voldemort would too and would not have made it a requirement unless he was sure no harm would come to that which this was all in place to protect. "How he has done so, I cannot fathom…" Fiendfyre's caster could rein it in, a second caster could conjure more Fiendfyre and fight for control over the original lot, or phoenix fire could be used. He could not see how Voldemort could have used any of those methods, and was rather curious despite himself.

"Let's find out," Sirius said, then made a face. "Or, rather, let's hopefully not find out, because that'd mean it was out of control…" He shook himself and met Albus' eye. "Can you cast it?"

"Would you believe me if I told you I have never tried?" Albus asked.

"Yes," Sirius said. "But that's not very helpful." He let out a breath. "I haven't either." Nymphadora gave a jerky shake of her head. Sirius eyed her, then looked back at Albus. "You, or me?"

"Would you be willing?" Albus asked, a little surprised.

"Would you?" Sirius asked. Albus didn't have an immediate answer for him; if it was necessary, he would do what had to be done, but would he do it willingly… "I'm a Black," Sirius said. He grimaced. "Might be some advantage to having me do it—dark magic runs in the blood, right?" He made a valiant attempt to smile and didn't quite manage it.

"I'm a Black too," Nymphadora said, putting a hand on his arm.

"Your dad's muggleborn," Sirius said. "That probably dilutes the darkness." This time, he did manage to smile. "Besides, we know you can hold it off, at least for a bit. You've done it before." Nymphadora gave a sharp nod, but Albus thought she looked relieved. "And so have you," Sirius said, looking at Albus. "If I lose control of it, you've got a better chance of keeping us alive than I do."

Albus could not—would not—argue with that. He inclined his head.

"Do you know what to do?"

"Not at all," Sirius said.

"It's Pestis incendium," Nymphadora said, eyes faraway again. Sirius murmured the words a few times, and then Nymphadora seemed to refocus, and her expression turned resolute. "If Pettigrew can do it, you can."

Sirius bared his teeth.

"The wand movement is this," Albus said, and knelt to draw the jagged shape into the grime on the floor.

"Frigus Ignis," Sirius murmured, tapping himself on the shoulder. "Not that I think it'll do much, but…"

"Every bit counts," Nymphadora said, and copied him. Albus did the same, mainly to make the pair of them feel like it was not a wasted effort; he was quietly sure it would not help at all.

Sirius lifted his wand, expression focused, but Albus held up a hand to stop him. Sirius froze. Albus lifted his arm a little higher, expectant, and elbow crooked.

A few seconds passed, but then, with a burst of fire that made Sirius jump and Dora's wand spurt water, Fawkes appeared. His weight was warm and comforting on Albus' arm, but he did not stay there; he hopped up to sit on the mantle.

"When you are ready, Sirius," Albus said.

Sirius took an audible breath, glanced at the shape Albus had drawn, and slashed his wand through the air.

The heat was immediate; Albus stepped back, as did Nymphadora, their wands coming up in unison to try to contain the heat. Fawkes trilled and spread his wings slightly, basking in it.

Fire spurted from Sirius' wand, and he did an awkward shuffle to get his feet out of the way, then leaned forward, aiming it at the hearth. It twisted and crackled and Sirius' brows drew together.

The damp, rotting wood around them was beginning to steam and sizzle.

The fire began to take shape.

Left to its own devices, Fiendfyre would form any variety of dangerous, flaming beasts, but while it was under control, it would take a shape unique to its caster, a little like a patronus. Often, it would take the shape of something which made its caster feel powerful; Voldemort favoured serpents, of course, and Peter Pettigrew's fire had taken the shape of a lion in the forest. Albus had seen Severus use both snakes and a phoenix.

Sirius' form may have made him feel powerful, but Albus suspected it had taken that shape because it was familiar; it was one which moved in—to Sirius, at least—predictable ways, and which he was used to controlling; it was distinctly canine, with shaggy, flaming fur, eyes that burned with savage intensity, and white-hot teeth in a mouth which slavered liquid fire onto the hearth.

"Can— I— call it— back?" Sirius gasped.

"Nothing's happening," Nymphadora hissed to Albus, and she was right.

Albus twisted his wand, then lifted his free hand to trace a quick rectangle in the air; through it, he could see the rune. It was drinking in the fire dripping onto it, and glowing a little more strongly than before.

Of course, Albus thought, with dismay and rather grim appreciation; it was not just the presence of Fiendfyre that was needed to satisfy the rune. Tom could wield Fiendfyre with precision—that Harry had survived receiving the burn on his chest in June was testament to that—so holding it for an extended period of time would be no challenge to him. The rune needed a certain amount of exposure, or to reach a certain temperature, perhaps, and there were few, Albus suspected, who had the control to grant that.

He did not think Sirius was one of those few, though he was doing an admirable job so far. Better, Albus was quietly certain, than he himself would have been able to do.

Even as Albus watched, the dog lunged toward them; his spell and Nymphadora's kept it at bay, but as it moved away from the hearth, the rune dimmed slightly.

"Hold it," Albus told Sirius, as calmly and firmly as he could manage. "Release no more now, Sirius, just hold what you have, and it must be there on the hearth—"

"How— long?" Sirius said through clenched teeth; his entire body was rigid and his hair was plastered to his face with sweat. The flaming hound shifted back onto the stone and the rune brightened at once.

It continued to drink.

"For as long as it takes," Albus said grimly. "Nymphadora, keep pressure there—see if we can help him contain it above the rune—"

"Right," Sirius gasped. "Good, I'll— just—"

One of the rotted rafters above them burst into flame.

"Ignore it," Albus said to Sirius, who'd jerked backward. "Focus on your task, Sirius. Trust us to handle the rest."

Nymphadora doused the roof with a hasty spell and as her attention moved, Albus felt the Fiendfyre pushing back against his own spells, felt the heat in the house spike. Several of the dry leaves on the floor began to smoulder and smoke.

Sirius coughed. He was red-faced and beginning to shake. The rune was still brightening, but not quickly enough.

"Hold it," Albus said, and Sirius snarled.

Several of the leaves caught fire properly and by unspoken agreement, Nymphadora dealt with them and cast charms to cool the rest of the house while Albus helped Sirius keep the dog in place.

It paced restlessly, as if caged, but that was all right, until it wasn't:

It lunged again, but not at Albus or Dora this time; at Sirius.