Disclaimer: This is JKR's world, altered to fit my own devices.

A/N: This is the sequel to my resurrection fic "Purity." So, call it an AU. "Purity" ended at Halloween in Harry's sixth year at Hogwarts. This story starts about a month later. And, yes, Remus and Sirius are lovers.

A clock ticked. Logs hissed and crackled companionably to the flames, not caring that the orange tongues would eventually devour them. A quill scratched a brief counterpoint across parchment and then stopped. The clock ticked on, ignored by the raven-haired man pondering the lists he'd written. There were three headings: ingredients, properties, and a vague estimation of how much of each ingredient was required. Reflectively, he nibbled on the end of the quill and debated about adding the next item.

'Runespoor eggs? Hardly anyone's mentioned them. Although, the books that list them seem more reliable than most of the rubbish I've read. But how the hell would I get my hands on them? Snape? Would he have any hidden in his office?'

An impish grin slowly slid across the thin features as Sirius Black imagined popping down unannounced to Severus Snape's quarters some evening. "Sorry to bother you, Snape, but would you happen to have some runespoor eggs that I might have?"

With any luck, his unexpected resurrection in Snape's life would cause the hated Potions Master to keel over dead.

The grin faded. Much as he would like springing full-formed and very much alive right in Snape's face for the shock value alone, for now his existence needed to be kept secret. A small group of people had witnessed his presence in the battle at the Department of Mysteries in June. And they had seen him die. However, his death had resulted from a fall through a veil, and there had been no body left behind. No evidence. No proof.

The Death Eaters captured that night hadn't talked. Without solid proof of Sirius' demise, they were unable to get his wealth and property into the hands of his closest male relative, Draco Malfoy. The Black estate was still beyond their grasp. But the Death Eaters were quite happy to let the Ministry continue to waste time and manpower hunting for him in the mistaken belief of his position at Voldemort's right hand, a thought made all the more frightening to the general public since the Ministry had acknowledged Voldemort's return. Rumor said that Lucius Malfoy had implicated Sirius as the strategist behind the Death Eaters' plot to obtain the Prophecy.

The members of the Order of the Phoenix had also kept silent about Sirius' presence that fateful night. Their silence protected the Black fortune and kept 12 Grimmauld Place away from the Malfoys. Plus, they still had no proof of Sirius' innocence to bring to the Ministry. Admitting that he had fought and died on their side would not clear his name legally or in the court of public opinion. And, even though Albus Dumbledore's reputation had been restored as a result of those events, he felt that the time was not right to make a case for Sirius' innocence.

But, of the people who had witnessed Sirius' death, only three knew of his return from beyond the veil on Halloween night. Ancient magic had come into play, summoned by his dead ancestors. The pact of Cognatus Putus, a pact that had arisen eons ago between the powers beyond life and the pureblooded families, had delivered him, body and soul, back to the living.

His return remained shrouded in secrecy. It was a weapon, blunt and unformed, but now being honed and tempered in preparation for a strike against one of those closest to the Dark Lord.

Sirius Black, convicted murderer, fugitive, and unregistered Animagus, now studied to push transformative magic to its highest level. He planned to do what no one in several hundred years had done successfully: become a Polyanimagus, a wizard who could change into any animal form at will. Then, he'd be ready to emerge from his secret lair at Hogwarts to hunt down Peter Pettigrew, wherever that rat lay hidden. If all went as planned, Voldemort would lose a close supporter, more of his treachery would be exposed, and Sirius would regain his good name and his freedom.

But, in order to accomplish this, he needed to develop a formula for the required potion. And that meant that any ingredients would have to be obtained by Albus Dumbledore or Remus Lupin. With vague regret, he gave up on his fantasy of sneaking out of his hidden suite of rooms to invade Snape's sanctuary.

Sirius' thoughts turned to a more pleasant subject. Remus. His beautiful, careworn, long-suffering lover, who was once more traveling alone for the Order. The sound of Sirius' voice echoed in his own mind, pledging a solemn vow to someone or something in the hazy memories he retained of his time beyond the veil. "I promise to bind myself for my lifetime and after my death, to a person of pure heart, whose ideals and actions reflect the best aspects of the blood purity out of which this pact arose." He had not mentioned Remus by name. But, his lover's presence in his heart had been as vibrant in death as it had ever been in life.

Sirius frowned at the clock. Time moved so slowly when Remus was gone.

The significance of the position of the clock's hands suddenly registered. Harry would be here shortly and Sirius couldn't let him get any hint of the Polyanimagus preparations. Rapidly, he rolled up his parchments. With a flick of his wand, he sent his flock of books and parchments flying through the adjoining room. They glided neatly into hiding under the large bed in the spacious bedroom beyond.

Sirius grabbed yesterday's Daily Prophet to skim the headlines before Harry's arrival. "Fudge Declares Progress Being Made in the Hunt for Y-K-W." "Sports Minister Says Quidditch Pitches Safe from Attack." "Family of Three Vanishes in Devon."

Sirius snorted with disgust. "Everything is perfectly fine, unless you and your family simply disappear."

He flipped to the back of the paper to do the crossword puzzle. Rapidly, he filled in half of the grid before tossing the paper down. With increasing irritation, Sirius wondered if he had become unbeatably proficient at this or if perhaps the current puzzle editor was an idiot. He snatched the paper up once more and flipped through it.

"Gringotts in Talks with Finance Secretary." "Twelfth Anniversary Celebrated by St. Mungo's Office of Single-Parent Births." "Renowned Purveyor of Crystal Balls Retires."

Sirius' eyes darted back to the story on single parent births He'd never heard of this office. Skimming rapidly through the article he discovered it had been set up because of the depredations suffered among families during the previous Death Eater war. But, the office had proven so popular that it still provided assistance to single witches or wizards who wished to have children. With a weary sadness, Sirius feared that their business would increase rapidly over the next few years.

The clock's hands seemed to have frozen. Remus was no closer to returning. Sirius concentrated hard, bringing up a perfect vision of Remus in his head, hearing the mellow voice chiding him for his sudden melancholy.

The ward on outer door unlocked to Harry's touch. He walked in and cocked an eyebrow at Sirius. "What have you been up to?"

Sirius blinked once. Twice. "I've been thinking," he said with complete truthfulness.

"About what?" Harry advanced into the room, dumping his book bag on the table. His look of amused doubt was so reminiscent of his father that Sirius got a slight feeling of vertigo, as if he was suddenly 16 again, trying unsuccessfully to hide something from the knowing eyes of his best friend. Mentally he shook the feeling away.

"Oh, all sorts of things. Politics, vacation spots, Quidditch standings..." His eyes flicked over to the clock.

"You mean you've been thinking about Remus."

Sirius grinned. "Am I that obvious?"

"You look at the clock every thirty seconds when he's gone."

With a laugh, Sirius ushered Harry into the sitting room for their daily chat. "I'm hopeless, aren't I? Okay, take my mind off my missing werewolf, and tell me how you did on your Transfiguration test."

With a look of quiet pride, Harry did just that.

For most of his life Remus had tended to drift slowly into wakefulness. No longer. Over the last month, he'd wake bolt upright in bed as if hexed. Only the sight or feel of his lover sleeping peacefully beside him would calm his racing heart. Exhaling his pent-up breath in a long sigh, Remus would whisper three words, the same three words it had become his habit to murmur when he tottered at the edge of sleep at night. Three words, spoken not only as an affirmation but also, it seemed to Sirius, as a protective spell.

The driving rain clattered like applause against the windows. The wind shrieked with a banshee wail, careening around the turrets of Hogwarts. That's what woke him up this morning, Remus vainly tried to convince himself. He settled back beneath the covers into the warm nest that cocooned their bodies. His hand gently stroked once down the smooth skin of Sirius' back before Remus snuggled up against him. "I love you," he breathed, and allowed his body to go back to sleep.

His mind, however, had other ideas. Last night Sirius had brought him up to date on the research into the Polyanimagus Transformation, calmly informing him that it was time to brew the potion. That Sirius hadn't yet done so; that he'd waited until Remus returned from his latest trip on Order business both pleased and surprised Remus. He knew Dumbledore contributed ideas and suggestions to the complicated preparations for this Transformation. And, if both Sirius and Albus felt that the formula for the potion was correct, there really was no need to wait for Remus' presence to commence the actual brewing.

Yet, Sirius had waited. True, there was a higher degree of caution and deliberation in all of his lover's actions since he had returned from beyond the veil. But, Remus thought there was something else. He was positive that Sirius sensed Remus' unspoken fear of losing him for a third time.

Remus snorted quietly. 'Am I really that needy?' he wondered, and decided, that, yes, right now, he was. He adjusted his limbs more comfortably around Sirius, and nuzzled his face into the thick, black hair. Remus regretted it wasn't nearly as silky as it had been years ago. But it had lost much of the coarse, lank feel that had dulled its luster after years in prison. Like many of his lover's physical attributes, that once-glorious hair seemed to be on its way back. With a contented sigh, Remus relaxed. A little more sleep would be good.

His brain refused to cooperate. Instead, it began to pull out everything they had discussed the previous night. It examined thoughts and reasoning from every angle, probing the gaps in their knowledge, seeking mistakes in logic or assumptions.

Like most advanced and potentially dangerous magic, the process was not laid out like a recipe in a cookbook. The potion had to be created from scratch because the precise amounts of the necessary ingredients differed with each person. The aspiring Polyanimagus had to decide how the various animal forms, whether mammal, bird, reptile, insect or fish, corresponded to his existing Animagus form, and adjust the potion ingredients accordingly.

Remus was out of his depth at this point. He understood the need for certain ingredients, such as gillyweed to help develop gills. Shrivelfig and moke skin for shrinking. Ground streeler shells for the ability to change colors. And even several questionable items like runespoor eggs.

But, he had no confidence of his own ability to develop a proper potion from these items, even with Sirius' detailed and meticulous explanation. The preparation of common household brews posed no problems for him, but he lacked the intuitive sense of potions and their ingredients that Sirius possessed. Sirius was quite like Snape in that respect, Remus mused, although he dared not mention that in Sirius' hearing.

Firmly pushing potion questions aside, Remus thought about the second part of the process, the mental application of magic, turning it inward upon oneself. The incantation required to channel magical energy towards shape-shifting into a different animal called for the utmost concentration, especially since a wizard needed to completely close his consciousness to his Animagus form.

He thought about last night's conversation....

"That's the key, Moony." Sirius said, after spending another long day poring through the mountain of tomes that Dumbledore had provided from Hogwarts' Library, checking and re-checking his research. His arms reached back over his head as he stretched in his chair, tilting it to a gravity-defying angle.

"You have to clear all thoughts of Padfoot from your mind? Can you do that?" A small frown creased the old-young face.

The upraised chair legs thudded to the floor. "Are you saying you don't think I have the mental discipline to handle this?"

"No, not at all!" And that was true, Remus reflected. The ability to focus all his concentration and skills with microscopic precision onto one problem had always been part of Sirius' make-up. Sometimes his solution was so elegantly constructed that Remus wished for a way to capture it visually, in a sweeping inspirational architecture of the mind. But, sometimes Sirius got so carried away with his own cleverness that he ignored the context into which his problem fit, with occasionally disastrous results.

"I'm not impugning your abilities, Sirius. But, Padfoot has played such a big role in your life that-"Remus stopped as a realization struck him.

"That what?" Sirius prodded.

Padfoot. Remus knew he had two merged perceptions of Padfoot. One was his and one was Moony's. Moony didn't know Sirius. Moony knew Padfoot, the big, black dog that had always been the most beloved member of his pack. The pull of Moony's bond with Padfoot was so deep and instinctual that it bled into Remus' perception. "I often think of Padfoot a separate entity, not as a different manifestation of you. That's not how you see him, is it?"

"I don't see him. Padfoot isn't some sort of costume. I'm Padfoot." Sirius was mildly perplexed that this concept seemed foreign to his lover. "That's the difficulty. How do I suppress the part of me that is Padfoot?"

Remus thought about that. "Let's assume that this works and as a Polyanimagus, you often transform into a squirrel."

Sirius sniffed disdainfully. "A squirrel?"

"Perhaps a small rodent isn't the best example," Remus conceded. "Alright, let's say an eagle."

Mollified, Sirius nodded and Remus continued. "Does the eagle become another part of you, an equal to Padfoot?"

Sirius wormed a book from the midst of his bibliographic heap. Remus scowled slightly when he saw the title: "Higher Transformations: Unproven Theories."

"A bit redundant, isn't it? Aren't all theories unproven? Isn't the lack of definitive proof the reason they're called theories?"

"Stop being pedantic and listen." The old pages crackled against Sirius' nimble fingers until he found the passage he sought. "'Should a Polyanimagus take a particular form or favor one form above all others, he risks splitting his animal identity too finely, putting in jeopardy the primal and unique relationship already existing with his original Animagus, which, in turn, may result in incomplete or mangled transformations that may or may not be occasion of severe bodily harm, or, even should the transformations be completed to perfection, an increased mental strain or impairment caused by the extreme effort required to keep these multiple and repeated personifications separate, unless the wizard has sufficient strength of will and power of mind to overcome these difficulties.' "

Sirius closed the book with a satisfying thump and tried in vain to hide his smirk at the disapproval on Remus' face. "You're just itching to grab a quill and start editing, aren't you?"

"That was a run-on sentence of gargantuan proportions. Is the whole bloody book like that?"

"Pretty much."

"And all you've gleaned from is it that powerful wizards might become successful Polyanimagi, assuming they don't do themselves mortal physical damage or drive themselves mad in the process?"

"An excellent summation, Professor."

Remus turned somber. Vague instructions and sketchy outlines made him deeply uneasy. But, the mental puzzle and the potential risk no doubt held a very strong appeal for his lover.

"Are those other books any more reassuring?"

Sirius was silent for a moment.

"I can do this, Remus." All his levity had vanished.

Remus stared hard at Sirius. Even though they'd discussed every step in the process, alone and with Dumbledore, he still worried about the possible dangers. But, his concerned frown gradually softened. This task was so important to Sirius on so many levels, not the least in its effects on his mental and emotional state. He finally had a task to perform that used some of his best abilities. And the change this had wrought in him from the man who'd spent long months locked up in Grimmauld Place was almost unnerving. He seemed totally different, so unlike the angry, bitter person he had been.

Remus' warm hazel eyes traced over the beloved face across the table. He saw strength and determination in Sirius' lean features, as well as a certain hard-won wisdom. Even if that face never lost its gaunt cast; even if the clear gray eyes always mirrored more melancholy than laughter; even if the shadowy specters of his nightmares lurked just below the surface, Sirius still possessed a bruised beauty that pierced Remus' heart...

He smiled at the impotent howling of the wind from the comfortable hollow of his bed. They had not lingered long at the table, for Remus had felt compelled to rise from his chair and allow his fingers to follow the path his eyes had already traveled. Caresses led to kisses. Kisses led to bed. The wind picked up during the night, but its mournful dirge was no match for the satisfied moans and contented sighs that had escaped their lips. It could not touch them.