Fic: Children's Moon, Chapter Five (HP/Who, Sirius/Jack Harkness)

[st_aurafina]

Fen had not returned from his night's work, the Gribbocks said. Sirius looked up at the sky as he ran through the forest; when the trees thinned, he saw a morning blue, with soft white clouds. The howling continued, though, despite it being well past sunrise now.

"Werewolves don't manifest in daylight," he said to the Doctor, who galloped at his side, an ever-present dark and whiskery shadow. "As soon as there was enough light to see, Remus always became human again."

"Maybe it's stress? Or this Dementor?" The Doctor leapt over a fallen log, paused to pick up the scent again and turned them to the north. "

Sirius had his wand out, ready for any surprises. "Anything is possible, with a Dementor," he said. "And it sounds as though Fen has plenty for them to feed on. Poor boy." Sirius wanted to run – anywhere, to the Red Lion Inn, or the TARDIS, or to the train station to take him to London, even if it wasn't London of his time, but all he could think of was what that boy had suffered, still a child, really, in the arms of Dementors. If he could make some of that right, he had to try. He wondered if he could still cast a Patronus, after all that had happened to him. The idea of facing a Dementor turned his stomach. He suddenly missed Remus so intensely that he tripped and stumbled. He stopped to catch his breath, leaning into the solidity of an oak tree. He could feel a thin sheen of sweat across his forehead. Another baleful howl echoed through the forest, long and reedy. All around them, birds fell silent.

"Och, there goes another one," said the Doctor, prancing belly-deep through the fallen leaves, ears pricked forward. "Another optical amplifier. Perpendicular to the first. Someone's building a fence out of light – probably Jack and his Torchwood mates. I wonder how they're managing with the ambient light levels?"

"Don't ask me," said Sirius. He leaned his elbows on his knees and rested his forehead in his hands. "I just want to get the Gribbock boy safe and secure." As if in answer to this, the werewolf screamed out his rage, and it echoed through the trees.

The Doctor tramped through the leaves until he could put his forelegs up on Sirius' knee. "You ken we might not be able to help him? First lesson of travelling with me: the days when you can save everyone are few and far between."

Sirius nodded. "To be honest, anything that comes after Azkaban is repair work anyway. I can't see how there's enough of Fen to make those repairs. A boy his age, he should be at Hogwarts, learning magic and making friends, and that's going to be impossible for a werewolf. It was hard enough in my time." He sat down cross-legged with his back to the tree trunk and pulled the Doctor into his lap, a warm and heavy mass of comfort.

"You had a werewolf friend?" asked the Doctor. "You understand a lot about the business of being a werewolf; I thought it was because you could do the whole transformation thing, but it doesn't seem to be the same."

"We all learned to transform," said Sirius. "So our friend wouldn't have to go through that by himself, we all learned a spell far beyond our abilities. God, we could have died, or been lost forever in our animal bodies, but what do you fear at that age?" He stroked the Doctor along his spine, smoothing the curly black fur.

"I know the feeling," the Doctor said. "Sometimes I wonder how I'm alive at all." His ears flicked forward and Sirius saw his nostrils flare. "That man with the woodlice is coming through this way," he said, with a warning growl.

"Probably looking for Fen, too," said Sirius. He put the Doctor on the ground and stood up. "Allaun!" he called out. "Are you there? Any luck with the search?"

"Hulloo!" came Allaun's answering call. He emerged from between two pine trees, a thick cudgel crooked in one elbow, his wand within easy grasp. "I spoke with the Gribbocks; they told me you wanted to help young Fen." There was something possessive in the way the boy's name slipped from his mouth. Sirius found his own hands had gone still.

"Indeed," said Sirius. "I've helped others before him."

"Have you, now?" Allaun drew closer, close enough to examine Sirius' face. He gave a dry laugh. "Oh, you're more like him than you've told anyone, aren't you? I see it in your face – you've been there. What did you do, then, to get sent to that hellish place? What did you touch that wasn't yours to finger?"

Sirius loosened his grip on his wand, so it hung easily and ready in his hand. "I want Fen to be safe," he said. "I think I can help him to understand how to be careful now. His parents want the best for him."

"I know what's best for him!" Allaun shouted. "I've always known what's best for him!" He raised his wand, and Sirius drew in his will for an attack, but before either of them could release a spell, a long grey blur shot past, and Allaun went flying.

There was barely time for Allaun to scream, before the werewolf ripped out his throat. He died quickly, his last breath and blood gurgling out of him, while the werewolf stood astride his body and watched. It was over before Sirius could even say the man's name.

"Fen," he said, standing quite still. Rapid movement would override any rational thought that Fen could muster. "Can you hear me, Fen? Come home, Fen, let your parents look after you. You don't have to kill anyone else." It was daylight, Sirius thought, it was possible he could fight the urge to kill. Remus sometimes became calmer, in the early hours of the morning, as if he could feel the power of the moon waning.

The werewolf turned and stalked towards him, snarling, with shoulders hunched and teeth bared. Sirius felt the Doctor's body bunch up at his heels, ready to leap forward in a futile attempt to stop him, but Fen's body shifted as he walked, first to a fur-covered human-shape walking on hands and feet, and then to a naked youth on two legs. He stared at Sirius with sunken, watery eyes. His canine teeth still protruded against his front lip and it gave him a slight lisp as he spoke. Blood streamed down from his mouth, staining the pale skin of his chest bright red.

"But I like killing. What if I want to stay like this and kill forever?"

Sirius was taken aback; he'd never seen a werewolf willingly, voluntarily change form before. "How are you able to do that?" It was the first thing that leapt to mind, even above Allaun's terrible death.

Fen laughed, his teeth stained red too. He pointed upwards to the sky, and when Sirius looked in that direction, he saw a pale moon floating against the morning blue. "This is the best time," Fen said, wetly. "The anger in the darkness is good, oh, so good, but the madness means I can barely get to enjoy it. But the morning moon is weak, and the change is easy. Back and forth I can go, and I get to choose who I hurt."

Sirius understood now how Fen had survived Azkaban; instead of fighting the atmosphere there as Sirius had done, Fen had soaked it up and forged himself into a weapon.

"Oh, laddie," said the Doctor in a sad little whine. "Oh, lad, I'm so sorry."

Fen looked down at the tiny dog, nonplussed, despite the blood dripping from his body and onto the ground. "What kind of dog has two hearts?" he said, and lifted his foot to stamp on him. The Doctor skipped out of the way and scampered to Sirius' other side.

"You don't have to be this way," said Sirius, desperately. "Don't let Azkaban shape you. Don't let the wolf shape you. Shape yourself. Be someone who matters. I did, Fen. You can too."

Fen drew closer to Sirius and leaned forward, hissing through his teeth. "I am shaping myself, don't you see? When I went away, I was Fen Gribbock, the doolally boy, a nobody boy. Now? I'm Fenrir now, I'm Fenrir and my back is grey, and nobody's going to fuck with me again." This last, Fenrir howled, and his muzzle extended as his eyes yellowed. He snapped great teeth at Sirius, dripping bloodstained foam. Sirius moved before he realised what he was doing, and with his foot planted square, kicked the werewolf hard in the chest. It only threw Fenrir a few yards, but it gave Sirius time to bring up his wand. His heart thumped in his chest with realisation and sorrow – this was Fenrir? Fenrir Greyback, who was going to grow up to join Voldemort, who would come across a young Remus Lupin in a garden somewhere, and would change his life forever. And Sirius had wanted to help him. Sirius had never cast any of the Unforgiveable curses, but he had the knowledge to do so, and the first mouthful of Avada Kedavra came to his lips.

Then a dark shadow slipped across the forest floor as clouds obscured the moon above, and all the warmth went out of the day. Sirius felt a familiar chill sliding down him like dank water, and all will to throw the curse seeped out of him. When the Dementor slid into the clearing, Sirius thought he would rather take on the werewolf: at least there would be blood and the passion of Greyback's hatred. The Dementor had a similar effect on Fenrir, whose leap fell short, and whose transformation halted halfway between man and wolf. He gave a terrified, pitiful whine, and, scrambling with his belly low to the ground, bolted from the clearing.

Sirius drew his wand, and reached for a memory, any memory that could bolster his chances of casting the Patronus charm, but nausea and sickly panic had chased thought from his mind. His mouth was so dry, he doubted he could even say the incantation. The Dementor drifted across the clearing, and, as if catching the scent of Sirius' terror, turned sharply in his direction.

A whiskery cold nose pushed into Sirius's palm, somehow grounding and reassuring. "Change me back, Sirius," said the Doctor, calmly. "You can do it – just wave the wand and change me back." He turned and trotted out towards the middle of the clearing.

It was a simple thing to release the transfiguration on the Doctor. Sirius gave a flick of his wand. The Doctor unfolded upward from the tiny dog's body mid-stride, and kept walking as if transfiguration were a thing he dealt with daily. He put two fingers to his mouth and gave a ripping whistle. The Dementor jerked in midair as if pulled on a string. It was so close that Sirius felt rotting grey tendrils of cloth brush his forehead as it turned.

"Oy! You, the sad flying mop! What do we call these things, Sirius? Dementoids? Oy, Dementoid! Have I got a feast for you!" The Doctor flung his arms wide. "Come and have a taste."

"Doctor, run," croaked Sirius. The Doctor was not a wizard, he had no Patronus, he wasn't even human.

The Dementor swooped towards the Doctor, and he held out his hand for it, snatched at the tattered cowl and hauled the thing down towards him like a balloon on a string. "You're one creature. You think you can drain everything wonderful I've seen and felt? I've seen galaxies born."

A familiar, horrible rattle came from the Dementor as it began to feed. Streams of light poured from the Doctor, and still he stood there with a grin on his face. "That's it. Suck it in. I've stood in a dead sea while life coalesced into being. I've seen a billion people push hatred aside in a single moment. Singing crystals the size of stars. Hot air balloons rising up in the morning – ooh, I love that. Birds made from light. Those big, wet, doggy kisses which should be disgusting but are filled with such joy. Ten lifetimes of things I've seen, so much love, so much beauty. One soul can't contain it; I barely can. You're just a thing. And you know what? You're a small, petty thing at that."

The hungry rattle became a wheezing cough, and the Dementor sunk lower in the air, so that the cowl draped the leaf-covered earth. Still the Doctor kept his grip on the thing, gazing into the hood, unafraid. "Come on, buddy. You can do better than that. Bumblebees in the sunshine. That first drink of water when you've thirsted for a year. That's it. Eat it up. You don't want to stop, you'll keep going until…"

The Dementor hit the ground with a solid, meaty thud. Sirius stared at the pooled grey of the cowl, astonished. It started to break up immediately, a dirty frost melting away in sunlight.

"Did… did you kill it?" Could Dementors even be killed? Sirius tried to push himself upright, but his arms and legs were still as weak as thin custard.

The Doctor poked the remnants of the thing with the toe of his trainer and shook his head. "I doubt it. I'm not sure it was ever really alive to begin with." He left it, and walked to where Sirius still sat on the ground. "Here," he said, and held out a hand. When Sirius took it, he pulled him upright with one smooth motion, and threw his arms around him in a hug. Sirius started, then stood, leaning into the Doctor's strength and warmth and friendship. Fear and sadness seemed to stream out of him and into the ground, until he finally felt he could stand alone.

His chin on Sirius' shoulder, the Doctor gave a chuckle. "Hah. Dementoids."

Sirius remembered his first aid, and took out the dusty chocolate bar. He snapped a piece off for the Doctor, and ate the other half himself, walking about the clearing and chewing. Chocolate worked: warmth and sugar settled the last of the anxiety.

"Serotonin," said the Doctor, indistinctly. "Good old serotonin. And caffeine. Also good."

"I knew him," said Sirius, with his thoughts finally ordered. "Fenrir, I knew him. I fought him, in my time. He's going to do horrible, devastating things."

"Oh, dear," said the Doctor. He licked the tips of his fingers, and pulled Sirius back into a hug.

For Sirius, the words were spilling out now, fast and unthinking. "You say we mustn't do anything that might change the timeline, but he's going to hurt someone I love, so much. So very much. Doctor, I can't not try to stop him."

The Doctor took him by the shoulders and held him away to look into his face. "No, you can't, can you? I see that. Then, we'll go. I won't ask you to be someone you're not, and I won't wave temptation under your nose. But before we leave, I want to get my hands on Jack's optical amplifier." He held out his sonic screwdriver and twirled it in his fingers. "I can't help Greyback, not after so much time has passed, but I think I have an idea about how to help old Farmer Willoughby."

"Help him with the transformation?" asked Sirius. "There's nothing much that can be done, not until they discover the Wolfsbane Potion around the time that I… that I left Azkaban." He said the last in a rush, forcing the words out. He was done stammering in fear when he spoke of that place.

The Doctor watched him, speculative. "It's very early in the infection stage. Lupine Wavelength Haemovariform infiltrates cell by cell; if we act now, we might be able to eradicate those cells before they get a hold on him. Unlike poor Fen; I don't think there's any chance we could separate those two entities at all now."

"I don't think Fen wants to be separate at all," said Sirius. "He really thinks it's made his life better. Stronger and better."

Somewhere in the forest, Fenrir bayed at the fading moon, and the Doctor looked off in that direction. "The real truth – the scary truth that frightened people cannot bear – is that stronger is not always better. There's strengths and there's strengths."

Sirius thought of the Doctor, standing unafraid while the Dementor hovered above him. He nodded. Then he reached for his wand. "If we're going near Jack, you'll need to be in disguise again."

The Doctor sighed and slumped his shoulders. "I suppose you're right. But the novelty is rather wearing off." He brightened. "Can you do any other dogs? What about those Old English Sheepdogs?" He gestured at his forehead. "With the floppy hair. All grey and white."

Sirius thought about the wording, and pulled the spell together in his mind. Before he cast it, he put up his wand. "The last time we tried this, the results were not predictable."

"Ah but this time I know what to expect. And I'm focused, Sirius, my mind is a keen laser, ready to help guide this spell properly." The Doctor shook himself all over, muttering to himself. "Be the sheepdog. Be the sheepdog."

"Hárasteorra!" Sirius released the spell and waited for the Doctor's form to stabilise.

"Did it work? Did it work?" barked the Docter, in melodic tones.

Sirius looked down at the corgi. "Yes," he said. "Yes, Doctor, it worked wonderfully."

Chapter FourChapter Six