A/N: This story has been mostly written for months and sitting around waiting for a couple of finishing touches. I've had a mostly free Saturday, so it's complete now and I will be uploading a chapter once a week on average.

Those impatiently awaiting updates of my other stories: don't worry! Neither Visionary nor Nothing like Harker have been forgotten. I just had to unload a bit of stress during the exam time (in May), so I came up with this. I was supposed to be my late birthday present to myself. Hope you enjoy it as much as I did.

I didn't intend this when I started. I thought it would have been nice if Harry had grown up with Bill in Egypt, right? Well… wrong.

Anyhow, warnings: completely AU and mostly OOC, very dark, violence, abuse, mentions of het, implied slash, very much not nice Bill and Harry, recreational Molly-bashing (I don't like Molly Weasley – can you tell?), character death, no happy end. Read at your own peril.

Inspiration acknowledgement goes to Elizabeth Knox and her creepily amazing Black Oxen.

Logical Fallacy

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Book One: Post Hoc Ergo Propter Hoc

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Chapter One: Deduction

x

"I dare you…" Silvia Fawcett paused and looked around the haphazard convention of mostly Gryffindor seventh-years. The glass in her hand teetered and Firewhisky sloshed onto her shirt. Her eyes fell on Timothy Masen draped over an armchair in a fashion that lay doubt to his consciousness. His eyes were open, but his cheek was pressed into a pool of his drool. "Timmy!" Silvia exclaimed, excited. "I dare you to wear my clothes to breakfast tomorrow!"

Impressed by the cleverness and hilarity of the rather unimaginative dare, the drunken company jeered and giggled. Timothy roused himself to half-way coherent state (which, in fact, was impressive, considering how much he had consumed when he had realised that against all odds he had graduated successfully) and blearily stared around himself.

"I bet he's got no idea what just happened," Adrian muttered near enough to Bill's ear to be heard. Bill didn't accept the bet, because it was rather obvious that Timothy was off with pixies in a land where bottles of whisky grew on trees, or perhaps bushes.

"I think Silvia could have him dress in her clothes right here, right now, in front of everybody. He wouldn't notice," Bill replied.

Adrian hummed. "I wouldn't mind seeing her in the buff," he said lecherously.

Bill laughed it off. As opposed to Adrian, he had seen several girls naked. While nice, he preferred to watch in private.

"I…" Timothy slurred, absently wiping spit from his cheek. "I'll do it 'course…"

Bill sighed. He sincerely doubted Tim was going to be able to go anywhere by breakfast. He would hardly be in the state to crawl out of bed… or armchair…

"I dare…" Timothy swayed, squinting in the absence of his glasses. It was possible that he couldn't recall a single of his classmates' names, so he searched for an impulse to spark the memory somewhere among the blurred faces of his audience. He stopped on the vivid red of Bill's hair, and Bill suddenly felt as though someone had stepped on his grave. "B-bill…to…"

Silence reigned and Adrian pulled away as if Bill was revealed to have a contagious illness. Grave eyes gazed at Bill from all sides as his so-called 'friends' expected his humiliation with bated breath.

In that very instance, William Weasley became aware that taking part in an Oath-bound game of 'Do you dare?' was one of the stupidest things he had done in his life.

"…to…"

He tried to convince himself it would just be something disgusting, something that had crept out of the alcohol–saturated recess of a diseased mind. Or something naked. Or, if Timothy was unexpectedly struck by a lightning bolt of inspiration, perhaps he would dare Bill to kiss a teacher or something, though hopefully not Sn-

"…to… I know!" Tim, in his excitement, slumped, and Bill had a second of hope that he was out, but then he opened his eyes and hollered: "I dare you to find Harry Potter!"

x

Bill ghosted up the Burrow's stairs, eluding his mother, who was in the kitchen teaching Ginny some housewifely knowledge, successfully reached his room and, once safe inside, let out a resounding sigh of relief. He was having one hell of a day…

He let his bag fall onto the floor with a hearty crunch of crumpled leather and parchment, cast off his robe and flopped down onto his bed. The day was sweltering – though it had not seemed so in the basement of Gringotts, where he had spent the past five hours. He was, nevertheless, glad to be out of there. Goblins in large numbers still made him nervous; he liked their attitude, but they were unpredictable and therefore slightly frightening-

"Bill?"

He glared at the door and, consequently, at Percy, who stuck his head inside without the basic courtesy of knocking. It was just like Hogwarts, except that instead of annoying year-mates his privacy was being invaded by obnoxious younger siblings.

"Yeah?" he asked.

"How did it go?" Percy inquired eagerly. What bloody business of his was it? If Bill wanted to tell him, he would have done so already.

"Fine," Bill grumbled, glaring in the vain hope that Percy would get the hint and piss off. No such luck. Percy grinned and stepped inside the room as if he couldn't see Bill's scowl and couldn't hear the grinding of his teeth.

"What do you want?" Bill practically barked at the kid. He had no patience with little brothers who made it their mission to vex him until he blew up and hurt them. That was why the entire family was in Gryffindor: Bill knew how to inflict pain without leaving marks (his mother thought him the perfect angel, as opposed to Fred and George, who were dubbed notorious liars, and Percy, who had gained the reputation of a wuss) and still his brothers provoked him. The only one with enough brain to leave well enough alone was Charlie…

"You touch that, brat, and I make sure you can't sit down for dinner," Bill hissed when Percy reached out to touch his bag.

"I just want to know if you-"

"I don't care." Bill got up from the bed and practically towered over his kid-brother. Percy pouted. Bill picked him up by the scruff of his neck and chucked him out into the corridor. He slammed the door shut (it had been silenced by his accidental magic since before he had started at Hogwarts) and hexed the handle.

With a quiet curse, he went to throw himself onto the bed again. The goblins didn't care a whit that he had a puny student's body – they wanted him to have the strength, speed and dexterity of a Special Ops Auror! He had survived, of course, but everything hurt and it was only going to get worse in the next two days. He was tempted to make a trip to Diagon a buy a muscle-relaxant or something, but his funds were short and he needed to save as much as he could. Ergo – no comfort for him.

Still, it wasn't like he wasn't used to it.

He seriously contemplated just nodding off – the day was already dead, but his mother was liable to kill him yet more literally if he didn't crawl out and inform her that he was home… A knock on the door brought him back to full awareness and he forbade himself to resent it, because he would be going against himself if he did.

"Yeah?" he grumbled.

"Can I come in?" Charlie's voice sniped right back and Bill snickered. Charlie was his safety: the moment Charlie would stop understanding him, he would know he was too far gone. Everybody else was ignorable, but Charlie had to be noticed.

"Do," Bill bade him. A yelp from outside reminded him that he had hexed the handle… well, never mind. Charlie lumbered in, scowling. He was rubbing his hand and giving Bill a Snape-worthy glare, but Bill had learnt to ignore that kind of glares when he was twelve.

"Bastard," Charlie mumbled, seating himself on the edge of the bed, accidentally aiming an elbow to Bill's bare side.

Bill dodged and groaned in pain. "You know you're insulting your own parents when you call me that?"

"You're insulting them when you act like that. Makes it seem like they didn't teach you any manners-"

"They should teach the little brats to keep their noses out of other people's business," Bill grumbled. Charlie paused in the rubbing and looked at his palm. There was a red welt there – a legacy of a nasty but generally harmless hex – and Bill sighed and cast a mild Healing Charm. Charlie sneered at Bill's wand in envy, but it wasn't like Bill hadn't had to wait for seventeen years before he could use it – let everyone else wait that long, too. That was plain and simple justice.

"So, what was Perce wailing about this time?" Charlie asked, keeping his mouth shut about his jealousy and about Bill's temper. Apparently, Bill wouldn't have to get up to inform the rest of the family about his arrival – Percival had handled it for him with the grace of a wussy twelve-year-old girl.

"Kicked him out of my room. Not even literally," Bill dismissed the occurrence. Their mother wouldn't believe the tale anyway, and he was rid of the kid for another couple of hours. Not a bad result. "Dammit, I hate little kids…" he muttered.

"You're sure you're a Weasley?" Charlie asked, laughing. "I thought we're genetically predisposed to want a houseful of sprogs-"

"Maybe I am a bastard," Bill replied with a shrug. He didn't particularly care. He very much doubted he had been conceived out of wedlock – he had too many physical similarities with his father – but he honestly didn't give a damn.

Charlie didn't have a response to that. Instead, he switched to the topic that was the primary reason of his visit. "Did the goblins send you packing?"

Bill growled. It was his damnable pride (he privately believed it was inherited from his mother's mother who was born a Rosier and allegedly as snobbish as an arguably Light witch could get) that remained vulnerable to verbal attacks. Fortunately there were probably two people in the world who realised that, so he wasn't harassed too often. It helped that he didn't take shit from anyone. Even the Slytherins gave him a wide berth after he had cursed Jorkins with an obscure spell not even Pomfrey could identify and break.

"No," he said eventually. He had wanted to keep it silent, but, dammit, he wasn't going to let Charlie mock him! He was the best in the year, and the goblins could have fallen over themselves to draft a contract. "I'm stationed in Egypt, starting the first of August."

"Awesome!" Charlie exclaimed. He was being mostly sincere but, like always, a little jealous. He was mostly content to remain in Bill's shadow, but he was also the only one who realised the true extent of Bill's awesomeness – and he carried that with a little less grace that would have been prudent.

"Tell that to mother," Bill scoffed. "I'm thinking I'll just go and leave her a letter explaining where I've gone. I really don't want to deal with all the shrieking."

"So you'll leave us to deal with it," Charlie deadpanned.

Bill shrugged. He didn't claim he was a nice person.

"Bastard."

x

"William Septimus Weasley!" his mother shrieked. Bill jolted from the bed and, reflexively, cast a Colloportus on his door. A moment later his brain woke up enough to realise what was going on, and he added a couple more charms reinforcing the exit.

He pulled on the robe he had thrown over the back on his chair yesterday, grabbed his shoes and bag, transfigured a part of the wall into a door, jumped through, and reversed the transfiguration.

Charlie glared at him blearily. "What did you do now?"

"At a guess, she read my bloody mail. Two more weeks and, thank Merlin, I'm out of this madhouse!"

"You're antisocial, brother," Charlie informed him ever so graciously, with his face buried in the pillow. "First step is to admit you've got a problem-"

"I've got a problem. My mother is a sodding banshee."

Charlie's shoulders shook, but it wasn't clear whether he was laughing or crying over Bill's impossibility. He pulled his blanket over his head. Bill tilted the chair by the desk until all Charlie's dirty clothes fell in the floor, and then sat down.

"You're not going away?" Charlie inquired, making it strikingly obvious he wished it were so.

"I don't want to." Bill hated how his voice sounded weak when he said it, and how he shivered. He despised his own stupidity – one, one bloody time in his bloody life he did something stupid, and landed himself in this pile of crap. He mentally swore vendetta on Timothy Braindead Mason, who had to come up with the one thing that would put Bill and his future into jeopardy.

"But you've got to?" Charlie was frowning at him, sitting up on the bed. His hair was rumpled, and Bill briefly wondered in what state his own was, but he had bigger things to worry about.

"Got to do the dare," he replied.

Charlie suddenly became very loud: "Why would you-"

"Shut up!" Bill hissed. "The game was spell-protected! We were all oath-bound-"

"Why in the name of Merlin did you do something so stupid?!"

Bill opened his mouth to reply – something heated and riddled with profanity – but Charlie found his own answer faster.

"Your idiotic pride, right…" Charlie shook his head in exasperation. "You only have to see him, right? Just make sure that he's there and that's it?"

Bill nodded.

"It could have been worse."

Bill would protest, but he was all too aware that he was lucky Mason couldn't remember polysyllabic words when he said the dare. Finding the Boy Saviour was, clearly, the lesser evil, considering how many other verbs Mason could have thought of in that instant.

"Good luck," Charlie told him simply, and ostentatiously lay down and pulled his cover over his head again. Bill didn't feel like talking, anyway, so he just shrugged and Apparated away before his mother located him and laid into him – or tried to forbid him to go to Egypt. Like he would listen.

x

"You're kidding me…" Bill muttered, staring at the house in front of himself. It was – he glanced at his wrist – half past six, and he had, after almost twelve hours of reconnaissance and travelling, located the fabled 'Privet Drive'.

The place gave him creeps. It was like someone cast a replicating spell on one building and continued to do so until he filled the entire area. There were cars. He wouldn't say so aloud, but he had been briefly thankful for his father's embarrassing obsession with muggles, because otherwise he would have been likely dead – run over by one of those lethal contraptions. They were… well, ingenious, yes. They were. Considering that they apparently had not a smidgen of magic in them…

Anyway, a town with as little individuality as this made him afraid that the creature that captured and brainwashed the citizens would capture and brainwash him, too. Orientation was possible only by house numbers, and he found '4' swiftly. There was a big red car in the driveway, a couple of stairs up to a white door and shouting coming from the inside.

He grimaced; he had escaped one shrieking harpy in the morning only to find another by the nightfall. He couldn't hear a response, until about a minute later a man began to shout… but not at the woman.

Bill scoffed at the folly. Whichever self-righteous meddling self-important… headmaster put the Boy Who Lived with a dysfunctional family of muggles? Wizards and witches would have duelled for the privilege of raising the boy. Bill didn't like his own family much, but they at least weren't violent and they – admittedly – cared about each other.

He wouldn't have to be here for too long. Just catch a glimpse of Potter, and be on his way…

He Disillusioned himself and walked up to the window. There was a sitting room behind it, lit by a rectangle of light coming from the hall. He would have to go in, then…

He lifted his wand and was about to cast 'Alohomora' on the white front door, when he noticed the hum. It was faint – in the loud muggle town, only those who knew what to look for would even notice it, not to mention recognise. Wards. Of course. Even a headmaster wouldn't leave Harry Potter without wards.

Dammit!

x

Thoroughly chastised, Bill dragged himself out of the Burrow. His mother followed him down the stairs, but she could not match his agility and he was out of the front door before she evaded Fred and George who, accidentally, ended up in her path.

"William!" his mother yelled.

"I've got a meeting, mum!" he yelled back, and Apparated.

He ended up in a park near the Privet Drive – an ugly place with a couple of swings, metal cage-like constructions with peeling paint and a dirty sand-box. He carefully watched where he was stepping, because the muggles that owned dogs around here didn't possess basic politeness.

"Young man!" an older lady surrounded by cats addressed him.

Bill did his utmost best to keep his face expressionless and turned to her, replying in an even voice: "Yes, ma'am?"

"This is muggle neighbourhood," she informed him, as if that wasn't obvious from the pathological uniformity. "That-" she pointed a gnarled finger at his robe, "-is not inconspicuous. Go get changed before I call Aurors on you for a breach of the Act, yea?"

Bill blinked. His attire was the last thing he had worried about, but he probably should have. In hindsight, it sounded quite like something he should be ashamed of overlooking-

"Thank you for the warning, ma'am," he said. He glanced around – there were a few people in sight – and cast a slow transfiguration. There was no immediate apparent change, but his robe gradually draped itself tighter around his torso and shrunk into a shirt. No one noticed.

"Nice piece of magic," the old lady nodded, while one of her cats (a little fluffy ginger monster) rubbed itself against his shoes. He gritted his teeth and rigidly held himself straight, trying to defy the urge to kick it. "Now, what is a young wizard like you doing in town like this?" she inquired curiously.

"I'm on a dare," Bill replied, biting his tongue before he quite rudely demanded that she tell him who she was.

She narrowed his eyes at him, and Bill decided then and there that he didn't want her to know. Moving faster than even the cats could react, he cast an 'Obliviate', and ran off across the park, with three enraged animals on his heels. He crossed the copse of trees and came out on the other side. There were more identical houses there. Bill turned right and at the next crossroad doubled back.

He came to Number Four Privet Drive ten minutes later, from the other side. A boy was yelling from the kitchen, demanding more food, and a woman replied in a high-pitched voice that carried, though her words weren't discernible. The ward hummed, even less noticeable in daylight than it had been in the dusk yesterday.

"Ouch…" someone said quietly.

Bill spun. There was a freshly-painted fence – bright white like the door – and behind it rosebushes in bloom. He came closer, as close as the ward allowed him.

There was a boy kneeling in the dry dirt, digging – no, spudding – with a tiny spade. He had messy black hair and wore a t-shirt that would have fit Bill better than it fitted him (even Bill's siblings had never worn clothes in such a loathsome state, not even for yard-work). Though Bill had never seen a picture of him, he was almost certain this was Harry Potter.

Fine. He had seen him. He could go now-

Potter sat back on his haunches and looked up, pushing a pair of round spectacles higher on his nose.

Bill froze – the boy had a bruise covering a third of his face. He had only seen such bruises after nasty Quidditch accidents, but here – in this pinnacle of muggleness – Potter couldn't have been playing Quidditch, not to speak about the fact that he was seven and therefore unlikely to be allowed a broom.

A pair of confused green eyes met his, and Potter flinched, hunching his shoulders. He swiftly returned to work, as if afraid that Bill would blab that he had taken ten seconds of rest.

"Who did that to you?" Bill asked.

Potter flinched again, but didn't look up. He kept on digging. Taught not to talk to strangers, naturally.

"I'm Bill," Bill said. "You're Harry, right?"

The boy didn't react. Bill was almost worried that he was deaf, but when the woman with the shrill voice shouted something from the house, Potter looked up and yelled: "Yes, Aunt Petunia!" in a high, childish voice. He reminded Bill of his brothers, but at the same time not.

Potter got up, washed his hands with the hose, and went into the house, successfully disregarding Bill's presence. It was nearly as offending as it was intriguing.