The night was his time, when he felt most alive, when he shed the conventions and inhibitions created by his vow long ago, and was free to simply be his true self. The self he kept hidden from everyone, the self that no one now living knew. The moon was full tonight, he could feel the shift in his blood, and he felt the old longing stir in him, the urge to run with only the moon to light his path, to put aside the controlled persona he affected and allow himself to be the wild untamed creature at his core. He looked up at the clock on the wall. Almost midnight, and long past the hour when students should be asleep.

This once, he would forsake his duty and indulge himself. Even he deserved a break now and again, especially after the events of the past year and the Triwizard Tournament. Decision made, he spun, his boots tapping rhythmically across the dungeon floor, and made his way out of the castle through a secret exit learned long ago during his schooldays. He walked past the greenhouse, past Hagrid’s hut, up to a large swath of green pasture, close to the Forbidden Forest, where sometimes the thestrals grazed. But they never bothered him, they were gentle creatures for the most part, despite their fearsome reputation. Upon reaching the grassy verge, he took three deep breaths, focusing himself.

There was a stirring of magic and suddenly the tall Potions professor became a magnificent black stallion.

The horse stood, quivering in the moonlight, which striped his coal black coat with faint silvery markings. He was pure ebony, satiny black from head to hoof, save for a single marking upon his forehead, half-covered by his long forelock. The mark of the crescent moon, an incandescent fiery imprint that told those who knew the old legends and ways that he was a devotee of the Midnight Lady, Selene, the Moon Goddess. He had been initiated into her Mysteries at thirteen, as were all the Prince line, and he had served her faithfully ever since. Selene was not a demanding goddess, she desired above all things that her followers be free to choose their own path, to guard the helpless, and to defend those in need against the rise of Shadow. Selene’s warriors were those who walked unseen, who watched and said little of what they saw, secretive and sly, but trustworthy and a vow, once given, would be kept unto death.

Like the vow he had given to Lily, to watch over and protect her only child, to nurture the boy’s fledgling magical gifts, and to love the boy in her stead should she be killed in the fight against Voldemort.

He found the first part of his vow easy enough to fulfill, as soon as the boy had set foot in Hogwarts, Severus had become his unseen protector, the watcher in the shadows, making sure the foolish brat did not kill himself with his reckless impulsiveness. It drove him to distraction, the way the child continually put himself into danger, as if he was somehow immune to death, and it didn’t help that the senile old coot in charge patted him on the head every time he did so. Did the boy not comprehend that his mother had given her very life for his, and that life ought to be cherished? Why must Potter be a glory seeker, like his bloody father?

The stallion shook his head and stamped a hoof upon the ground. Thinking about James Potter always made his insides twist up, as if he had a bout of colic. And the boy bid fair to take after his troublemaking, arrogant father, at least from what Severus had observed so far. Severus had hoped that the child would have more of his mother in him than his father, but that did not seem to be the case. And that was what made fulfilling the last part of his vow so hard. How could he love a boy who resembled his arrogant bullying father so much, who was practically James Potter’s reflection? The only thing it seemed Potter had inherited of Lily’s were her eyes.

The stallion shook his head abruptly. No, he would not think of that, not now. This was his time to relax, to allow all of his pent up frustration and irritation at dull-witted students and impulsive cheeky brats to be released. This was his time to allow the wildness in his soul free reign and to run beneath the moon.

He half-reared, spinning about upon his hocks, his ebony mane drifting over his neck, tail flagged, and then he sprang forward. His hindquarters propelled him in a gigantic leap halfway across the meadow and then he ran, head high, his long legs flying over the ground in great bounding strides.

The black stallion was built along similar lines as the great Thoroughbreds, he had the same streamlined body and long legs, powerful shoulders and haunches, but his tail was set high, like an Arabian’s and his face was more tapered with large nostrils made to drink the wind and wide-set eyes of startling intelligence. Had anyone come upon Severus in his stallion form, they would have known here was no ordinary animal, even without the telltale crescent upon his brow. There was something otherworldly about the great horse, a grace, an uncanny intuition, when he ran, he did so without worrying about where to place his feet, unmindful of rocks or sudden holes, the dark was no barrier to his eyes. As a disciple of Selene, he could see in the dark as if it were brightest day, so long as the moon shone.

His flying feet pounded the dirt, kicking up spurts, and he stretched out his head, glorying in the feel of the wind as it whipped his mane into a froth and caressed his skin. This was what he craved, the sheer joy to run wherever he chose, to chase moonbeams, free from all the tiresome rules that bound him as a human. Here there was only the wind, the moon, and himself, racing his shadow around and around while far away a screech owl hooted and a dog barked.

He ran across the meadow and into the forest, weaving expertly in and out of the trees, springing agilely over a fallen log, his breath coming in sharp pants, but he did not slow, his endurance was far greater than a steeplechaser, and the moon granted him a strength beyond an ordinary horse’s. He startled a rabbit from its burrow, it fled before his hooves, vanishing into the undergrowth. He ignored it, continuing to run.

He jumped the small stream and raced up a hill to a flat piece of ground where a herd of unicorns gathered. He paused, tossing his head, and greeted the Lead Stallion, Amicus, who nodded and allowed him to come among his herd. There were five mares and two yearlings and three foals this season, all healthy and eager to race their dark brother, who had visited so seldom this year.

The dark horse trotted up and greeted each mare in turn, blowing respectfully into their nostrils. Well met, Sylvana, Silken Wind, Fortuna, Star of Albia, and Sirocco.

They blew back at him, nickering softly. Good evening to you, Moon Fire. Did you have a nice run?

He nodded his head, his forelock flying across his face, partially covering his mark.

Then the foals and yearlings frolicked over, golden coats glittering like new-minted Galleons, nudging and snorting at the big horse. Moon Fire! Moon Fire! Come and race us!

He snorted indulgently at them, he had more patience with the foals than his students, most of the time.

One particularly bold yearling sidled up, bumping hard against his withers. Race me, dark one! Bet you can’t catch me! I am Starblaze the Magnificent, and I can outrun the wind if I want. The colt challenged.

He swung about, giving the overeager youngster a firm shove and a sharp nip to remind him of his place. Settle down, silly colt! We shall race later, if you behave.

Chastened, the colt lowered his head and mouthed an apology, then backed away, allowing his elder to graze upon the tender shoots of sweet grass. But his reprieve was shortlived, as the other foals clamored to race also, running circles about the black stallion.

Me too! Me too! I want to race too!

A few more minutes and Moon Fire, as he was known in this shape, gave up on eating a late night snack and agreed to race the young unicorns. Selene’s All-Seeing Eye! I suppose I shall have no peace until I run the hooves off of you lot of impudent younglings.

Squeals of joy sounded from the yearlings and the foals, and they jostled about him, kicking up their heels and neighing.

A few of the overeager foals’ hooves caught him glancing blows, and he reprimanded them sharply with a nudge from his nose and a warning nip or two. Mind where you fling your hooves, you insolent nags! Or the only racing you shall do is running to hide behind your mothers from my teeth, he threatened.

Amicus whistled shrilly, Mind your dark brother, foals!

Yes, Father. Sorry, Moon Fire.

A snort came from Moon Fire’s elegant muzzle and then he squared up. Forgiven, you pests. Line up, and remember, no biting, kicking, or knocking into each other on purpose.

They all obeyed, and at Amicus’ whistle, surged across the ground, trying to outrun the dark horse whose hooves seemed to fly over the earth, the moonlight sheening his hide in icy rivulets, giving the ebony coat a bluish cast.

Silvery hooves flashed and golden horns gleamed as the unicorn foals and yearlings sought to catch the racing stallion, who always managed to stay just one leap ahead, running with a graceful swiftness that they envied and admired, even as they tried to slip past him.

None of them, not even Starblaze, who was the oldest, had ever managed to beat Moon Fire.

But that did not stop them from trying.

The big stallion flicked an ear back, gauging how far away his nearest competitor was, about two lengths, and deliberately slowed, allowing the colt to catch up, coming with a few strides of his forelegs before he increased his speed and drew away again, giving a mischievous whinny.

No fair! I almost had you! whinnied Starblaze.

So you thought, the other tossed his head and skipped about the sticks lying on the path, circling the meadow and then coming back around, to end at last in a thundering rush in the center of the grassy clearing.

The mares looked up from their grazing in amusement. Moon Fire wins again. Sylvana observed.

But my Starblaze was close, said Fortuna, blowing her forelock out of her eyes.

At least he’s tired them out, remarked Sirocco. So maybe they’ll sleep and quit jumping about like bluebottles.

Sure enough, the foals were tired after their run, and came to graze quietly beside their mothers or lie in the grass and nap, leaving the adults to graze and talk peacefully.

Moon Fire also grazed, barely winded from his run, his tail switching gently against his flanks, content among the unicorns, who embodied the wildness and magic and steadfast courage of the Goddess, who had made them from her breath and tears. Of all her children, the unicorn was the closest to Selene in spirit and those who worshipped her considered them sacred. That this herd had chosen to accept him, despite all he had done as a spy, was an unlooked for blessing.

He returned here each fortnight, to run with the herd, and renew his weary spirit, for the very air the unicorns breathed exuded a kind of peace and serenity he had known only in dreams. But it was something he badly needed, and they seemed to recognize that, and gave him it willingly and did not pry and ask awkward questions the way humans did.

* * * * * *

The moon slipped down in the sky and the dark horse lifted his head, sensing it was time to head back to the castle. Reluctantly, he bid farewell to the unicorns, and trotted off through the forest, his hooves making hardly a sound over the earth, his crescent gleaming in the darkness.

As a human he had been forced to bear a brand of servitude to a dark sorcerer, so he could learn that one’s secrets and figure out a way to destroy him, but in this form, he bore only the mark of his goddess, which was as it should be. He cantered through the trees and into the high meadow where he had begun his journey.

Suddenly his ears caught a muffled sound, a hitching and catching of breath, and he froze.

Something had invaded the meadow.

His nostrils inhaled the night air, and he threw up his head as he caught the unmistakable scent of a boy, and not just any boy, but the one who lived to drive him to drink, Harry James Potter.

His first instinct was to shift into his human form and demand an explanation of the disobedient wretch. What in blue blazes are you doing out here in the middle of the night, Potter? How did you manage to find this place and how dare you ignore the school rules put in place for your safety and wander about outside like this was the bloody Gryffindor common room? Don’t you know what could happen? Or do you want to get eaten alive by a wyvern or torn to shreds by a hungry musk cat or stolen away by a roc to feed her nestlings? Of all the stupid, reckless, idiotic, insane, utterly asinine things to do . . .!

He trotted forward, emerging from the trees to glide across the meadow towards where the boy was sitting, knees drawn up and head resting awkwardly atop them, hair sticking up all over like porcupine quills. Oh yes, I am going to give the damn insolent brat a good piece of my mind, see if I don’t! This is what comes of coddling and spoiling the little—

He halted abruptly, for now it was obvious why Harry had come out here.

The champion of the Triwizard Tournament was crying. And not just a few tears, but outright sobbing, shivering and gasping, crying so hard he was unaware of anything about his surroundings.

Shocked, Severus remained a few feet away from the distraught boy, his senses telling him that this outpouring of misery had been festering within the young wizard for a very long time before at last finding a way out. It brought to mind a time long ago, right after the death of the only woman he had ever called friend and had loved with all that he was. Just so had he wept, desolate and alone, hurting beyond bearing, until Amicus had found him and tapped him with his horn, easing some of the raw pain and giving him a comfort no human could.

What had caused the boy to cry this way? The big horse wondered. Was he crying because of some physical ailment or some other hidden grief? Perhaps the death of his classmate, Cedric? Funny, but he had never thought Diggory and Potter especially good friends. And what, by the light of the moon, was he supposed to do about it? He was no unicorn, gifted with the ability to draw poison from body and spirit.

He shifted slightly, blowing out softly, as he would have done to a frightened foal.

Harry felt the soft whisper of warm air upon his bent head and jerked up.

To stare directly into the eyes of the most magnificent horse he had ever seen, standing not four feet away in a patch of moonlight.