Karen was an unhappy girl. Why did she feel so different to everyone else? Maybe it wasn't obvious that she was different. She wasn't disabled, she didn't belong to an ethnic minority, she wasn't especially tall, short, fat or thin, and she was sure that she quite liked boys. Well, perhaps she liked them more as friends than as anything else, but she did feel more at ease in the company of boys than she did with the girls in her class.

Perhaps this was what made Karen sure that she was somehow different to the other girls in her school. Why she just never had that feeling of belonging, of being part of the team, or, even, and this really hurt, having a best friend like so many of the other girls had. Sure, she'd once had a best friend. That was Lucy, the tubby girl with glasses who was now spending all her time with Liz. But not with her! Ever since they had that argument over that hairbrush, and she even forgot why it happened, Karen no longer had a best friend.

But then most girls were stupid. Well, they had to be. Putting all that make-up on! Pushing up their tiny breasts to try and make them look bigger! Trying to look like some kind of magazine model or like one of the singers in the girl groups they liked. And for what? For boys who just didn't care anyway. They were more fun just as friends. Okay, you couldn't have a boy as a best friend exactly. Then he would be a boyfriend. And that might mean shagging or something, and Karen wasn't sure she was ready for that.

She enjoyed snogging. That was fun! That day in the woods when she snogged with Alex, Jim and Dave. And then, when they later met Pete, why! she snogged with him as well. And Jim even got to cop a feel of her tits. They weren't big tits by any stretch of the imagination, - just bumps on her chest with the nipples not really as distinct from the areola as she was sure they should be, - but it felt nice when Jim ran his fingers round and round them, while his tongue did battle with hers. And all the while, Alex and Dave were crying "It's my turn!" and "Hurry up!"

But girls? They weren't like boys at all, though there was something about them that made Karen feel very strange. It gave her a very weird feeling altogether. That time when she accidentally brushed against Emily's bare breast in the changing room after hockey. Although Emily just pushed her hand off and made no comment, the memory of that sensation persisted for hours afterwards. And why did she feel so much short of breath at the time? And did she really blush? Emily wasn't even the prettiest girl at school. She was a bit skinny and wore a brace to keep her teeth in place. But after that brief accidental encounter, Karen felt distinctly hot and flushed whenever she was near the girl.

She was troubled about her unfocused emotions. She stared at the bowl of macaroni cheese that her mother had scooped up for her, wondering whether perhaps the way she was different wasn't because she had some secret super-powers like the heroes in the television cartoons she liked to watch, but because she was queer. Maybe she was some kind of girl who fancied girls. But that couldn't be! After all, she enjoyed snogging boys, didn't she?

"Karen," her mother spoke to her, more as a command for attention than anything else.

"What?"

Karen's father frowned, but he didn't say his usual bit about her not being so rude. Karen's heart thumped in her chest. Maybe her mother was going to say something important for a change.

"It's about your sister, Po..."

"Po?"

"Or Pauline," remarked Karen's father, who'd always disliked the abbreviation.

"Yes, Po. When did you last see her, Karen?"

"Ooh, years ago! When I was, I dunno, ten or eleven or something."

"Yes, that's about right, Karen. About four years ago."

Karen's mother paused and regarded her husband with a slightly worried gaze. Karen could see that she wanted to stretch out her hand and grasp hers, but was anxious about how her daughter might react.

Her mother coughed awkwardly. "Po's coming back to live here, Karen. She was taken to a hospital in Islington where they identified her. It's been four years since she ran away..."

"Four years and three months," her father elaborated bitterly.

"And Po was younger than you when she ran off. And you know how worried we'd been, Karen dear. We loved her despite her being such a tearaway..."

"All that drinking and smoking and goodness knows what!" her father elaborated.

"But she's still alive. She's had a fairly rough time we think. She's been taking drugs and seeing strange men and living in the most squalid places and she looks such a wreck..." Karen's mother paused, and her daughter rather uncomfortably noticed that her mother was actually crying. A tear had trailed down from an eye to her chin, and shone in the early evening sunshine.

"It's a difficult decision to make," continued Karen's father. "She's not been very well looked after at all. No school. No proper education. Not even a hint of good manners or good behaviour about her. I hesitated... I mean, we hesitated... about having her here, seeing as she could be such a bad example to you..."

"But she is our daughter!" smiled Karen's mother, with a sad smile. "We love her, however bad or dissolute she might be. In any case, maybe it'll be the other way. Maybe, you'll be the good example for our older daughter. So, what do you think, Karen dear? Soon, you won't be the only one in the house besides your father and me."

Karen was wary, but delighted. She'd always thought highly of Po. She'd been so much fun as an older sister, all those years ago. She remembered the stories Po told her about boys and how she used to kiss and gobble their penises. She said it was called 'sucking', but you didn't do any sucking at all. She remembered those cigarettes Po shared with her. And that time Po let her drink some beer, which made her feel really funny for hours afterwards.

"Yeah!" she said. "That sounds cool."

"'Cool'?" sniffed her father.

"Not now, dear!" said Karen's mother impatiently. "Now, Po's been pretty ill. In fact, she almost died. It's something to do with the drugs she took. I think she took heroin and cocaine and some other drugs with funny initials like GBH, the doctor said. She was in a coma when the police found her in an alleyway just north of FinsburyPark tube station. Her clothes were in a very poor state and she had some nasty sores. She had some other health problems, related to sexual diseases..."

"But not AIDS," Karen's father interjected angrily. "How she missed that one I don't know! She got other ones though. Fine if they're treated, but left to fester..."

"Well, dear," Karen's mother interrupted. "What's done is done! Po's alive. She could have died! After all the worrying over the last four years or more of where she had got to..."

"And all along, she was living less than five miles away! She could have easily contacted us!"

Karen could see her father was bitter about this, but she was more focused on the fact that Po was coming back. That would be so much fun! Perhaps all she'd been missing was her older sister. She'd seen all those movies and television programmes where people had lost their older brothers or sisters, and when they came back, everything was wonderful again. And from what she remembered in the movies, wasn't all that time when your brother or sister was missing meant to be traumatic? Maybe that explained why she felt different from other girls. And now that Po was coming back, perhaps now she too would go through that magical transformation. She too would be happy and contented with her beautiful older sister. They could do sisterly type things together. Karen wasn't sure what it was that sisters did together, but she was certain that whatever it was, it must be good and wholesome and gratifying.

However, whatever image she had in her mind of what Po might look like - based on the prodigal daughters of children's television drama - did not prepare Karen for the real thing.

Po was much older than she'd imagined, having aged rather more than the elapsed four years since they'd last met. She was very gaunt, her red hair was straggly and uncombed, and although the clothes she wore were just an unremarkable pair of jeans and a tee-shirt, with that ring through her nose and the stud in her tongue, she might as well have been dressed in archetypal punk leather and tartan as far as Karen's father was concerned.

However, Karen noticed that he made no comment about this. Nor did he comment on her smoking, which she had evidently been doing for quite a while before Karen came back from school, judging by the stubbed filters in the ashtray and the pervasive smoke in the living room. And he also made no criticism when she swore, which she did frequently and with neither any sense of embarrassment nor even a hint that she was being intentionally provocative.

"Yeah, the cunt deserved what he got!" Po was exclaiming as Karen entered the room. "Fucking arsehole! I'd have ripped his other eye out if I'd the chance after the way he'd fucking raped me that time... And shit! Who's this little girlie?"

"It's your sister, Pauline," said Karen's father in a quietly restrained voice.

"Karen! Fuck me! She's fucking grown, ain't she? How're you, sis? You got a boyfriend yet?"

Karen shook her head. This wasn't quite the first thing she'd expected her long lost sister to ask her.

"Girlfriend then? You a les, then?"

Karen shook her head more adamantly and blushed, but secretly feeling pleased that her sister could be so open about something which had troubled her so much.

"Well! What's fucking wrong with you, sis? Here, have a fag!"

"Karen doesn't smoke, Pauline," said her father firmly.

"She doesn't? Well, good for you, girl! Nicotine's fucking poison, it is! I'd give it up tomorrow if I could! But when you're coming down, you know, from where I've been, I need every fucking prop I can get hold of."

With that, she opened up the packet of cigarettes, placed one in her mouth and lit it, while Karen's father pretended not to notice and her mother smiled ineffectually.

Karen didn't get much chance to actually say anything at all to her prodigal sister all evening. It was Po who did most of the talking, pausing mostly just to light cigarettes and take swigs from the cans of lager, the fetching of which from the refrigerator in the kitchen were almost the only times she deserted the huge sofa that had somehow become hers. Karen's mother and father sat around politely, occasionally emptying the ashtray or flicking ash off the furniture where it settled, while Po talked and talked and talked.

For Karen, it sounded very exciting indeed, though her parents were quite obviously appalled. Po had done everything, it seemed. She'd hung around with like real gangsters who'd fuck you up soon's they saw you. She'd done a stint of prostitution at King's Cross, till she figured that streetwalking was for mugs when all you needed to do was place a card in a phone booth. She'd done a bit of dealing, soft stuff mostly, but she'd graduated to H. Bit more lucrative, but not as much fun as selling E at night clubs. But lately, it had all got fucking out of hand. The smack had fucking done her in. She'd thought she'd be able to handle it. After all, her best mate, Griz, she'd been fucking mainlining since she was fifteen, and she was like, fucking twenty three now. Fucking ancient. And she was alright. She'd managed to handle it. So why couldn't Po?

"You couldn't though, could you dear?" interceded Karen's mother before her father could say something rather less tactful.

"No. I guess not! But it was fucking great for a while. I felt real cool. And with what I made from flogging the gear and the bit of extra from the punters, I was fucking rich, I can tell you. I could fucking afford everything!"

After a few days, Karen was able to spend more time with Po without her parents accompanying her. In fact, it was obvious that they were thoroughly exhausted from the effort of such chaperoning. Her father now spent most of the evening watching television in the living room, while her mother sat in the kitchen.

Po mostly stayed in her bedroom which had been reserved for her since she'd run away all those years ago. Karen liked to sit with her sister in her room, watching her puff away at her ciggies, swig at her lager, and, bolder now, toke off her thin single-skin spliffs. It was Po who did most of the talking, lying stretched out on her bed, flattening the duvet, while Karen sat there on the armchair. And what things Po talked about! As Karen got to realise, there was a fucking big world out there and a girl had to have her fucking wits about her to survive.

There was something a little incongruous about the setting though. As Po let forth about the things she'd done or heard about, which were of a distinctly adult nature, expressed in suitably adult language, the bedroom remained that of a girl in her early teens, and Po showed no interest at all in updating the décor. There were the posters of the boy bands she'd once enjoyed, the stacked-up CDs were compilations of dated juvenile dance music and the duvet still displayed a mosaic of friendly ponies and gruff looking teddy bears. But Po just didn't seem to notice much about her surroundings.

She once put on a CD that Karen brought in of some fairly weird techno that she thought her sister might like, but although Po made some appreciative noises, Karen could see she wasn't paying it any real attention.

But it was Karen who was learning the most. There were some pretty kinky people out there, men and women, who did the weirdest things. And there was a lot of violence, a lot of drugs, a lot of money to be made, and so much much more which made Karen's own fears, about her uncertain feelings towards girls and the fact she preferred being with boys, appear pretty boring really. Karen so wanted to tell Po about her life, but it would just sound so pathetic and boring compared to her sister's really cool life.

"I'm glad you spend so much time talking to Po," said Karen's mother one day as she was preparing to go to school. "I'm sure it does her a lot of good to talk to someone."

"Yes, Karen," agreed her father, who looked up over the front page of his Daily Telegraph. "I'm sorry your sister talks in such disgusting language, but your mother and I think it must be good for her to be able to talk to someone who doesn't take drugs or do any of the other disgusting things she used to do."

Karen nodded, but secretly she rather envied Po for her much more exciting past. And she also knew that though her sister wasn't taking heroin any more, she was dabbling in a few other drugs, mostly cannabis, but occasionally cocaine and sulphate. But the drugs weren't what Karen found most interesting about Po's life. It was the sex. And her sister expressed no sense of embarrassment at all as she talked about all the various sexual encounters she'd had, with men, women, groups of men, indeed, whole orgies!

However, although Karen's parents liked the notion that their older daughter was now, in a sense, a reformed woman, it must have come as a shock to them both when, one evening, having both returned from their different places of work, they arrived home to a kitchen where Po was sitting quite nonchalantly on the stool with no clothes at all, smoking a cigarette and occasionally biting into some chocolate sandwiches she'd prepared. And as Karen was soon to find out there was something rather shockingly blatant about Po's nudity. Her body was unmistakably that of a teenage girl, with a full brush of hair around her vagina, but the folds of her vulva fell right out and were visible to all unless she chose to cross her legs. And although her breasts were not very full, and she no longer wore the rings through her nipples that she apparently once used to, hers were still a bosom that Karen's father found difficult to look toward without embarrassment.

"I'm just fucking pissed off with wearing clothes, that's all!" Po explained it to Karen, when her sister visited in her room after some very anxious words of advice from her parents. "They fucking itch! And anyway if I don't want to wear clothes when I'm in my own home, why the fuck should I?"

Karen nodded, but rather inappropriate feelings distracted her as she regarded her sister's naked body. She'd seen naked female bodies before. How could any girl who played sports, and was even in the school girls' soccer team, not get used to seeing naked girls? But there was a difference somehow between the girls crowded into the shower with their puppy fat disappearing and their breasts not yet fully grown and a girl like Po whom Karen knew so well had a sexual character and was not ashamed to flaunt it.