Electra! Call 999! Lucy's choking to death!'

Bella Malone slams on the brakes of her humungous silver Range Rover, causing the Maltesers I've been scoffing to fly out of their packet and ping off the grey leather upholstery. It's like sitting in the middle of a confectionery- based pinball machine, but without the crazy music and flashing lights. I'm just glad I put my seat belt on. I doubt my head would bounce around like a chocolate-covered honeycomb ball, rather end up as chopped liver smeared across the dashboard.

It was only seconds after Luce popped the Maltesers I'd chucked her that she started flapping her hands and gasping as if she was being deprived of oxygen, so it's not unreasonable that Bella thinks her daughter is dying from inappropriate inhalation of sweets. I, however, remain icily calm, not because I have excellent first aid skills and am about to spring into action and save my best friend's life, but because we went through the same possible choking-by-confectionery routine yesterday, only in my bedroom with some wine gums rather than in Bella's car with Maltesers.

Luce isn't having a seizure requiring the kiss of life, the Heimlich manoeuvre, an ambulance and several days in intensive care strapped to bleeping machines.

She's just received the latest text from Josh, who's away doing something snow-related in France with his cousins. On New Year's Day, Lower Sixth-former, Dogs of Doom singer, guitarist and Lucy's new matching blond-haired boyfriend, Josh Caldwell, promised he'd send her a romantic text every day until presumably they either finish or he runs out of butt-clenchingly slushy stuff to write. Other than overexcited panting at inappropriate moments - the loo in Burger King, the front of the queue at the tills in Primark and so on - it's not really been a problem as we've been on Christmas hols, but we're back to school tomorrow and I can't see Mr Farrell interrupting his dissection of one of Shakespeare's great sonnets to allow Luce to hyperventilate over Josh's latest composition.

'She's not choking,' I explain, as behind us car horns start hooting aggressively. 'She's excited about her text message from luvver boy.'

'You mean I've nearly had a car up my backside for a text?' Bella sounds furious. 'You girls! You're all such teen drama queens.'

Hoping that Bella has her eyes on the road rather than the back seat, I poke my tongue out, just as Luce turns round.

'Read this one,' she sighs, handing her phone over her shoulder to me. 'It's sooo beautiful.'

I'm prone to barfing if I read in the car, especially in the back seat when travelling round corners at speed, and I'm sure Bella wouldn't appreciate having to make a vomit stop so soon after the emergency sweet stop.

'You read it, Luce,' I say, pushing the phone back and rummaging on the floor for Maltesers. Bella is such a Neat Freak you could lick the carpet mats without fear of picking up anything nasty, so I have no issues with extracting sweets from under the front seats and eating them. 'It's your slush.'

'Remember yesterday Josh said I reminded him of golden sunlight?' Luce gushes. 'Well, today he's said I'm like dappled moonlight on water.'

'What, wet and blotchy?' I say, wondering how long Josh can keep the solar system theme running. It's going to be challenging when he finally has to try and compare Lucy to Uranus.

'I know nothing about these texts,' Bella says sourly. 'But then Lucy tells me very little about what she's up to. I know more about your young man, Electra, than her Josh.'

'Oh?' I have a feeling Luce has been deflecting Bella boy- interrogation by talking about my love life rather than hers. 'Lucy says his mother's a doctor at the General and his father owns a computer company. They've got a fabulous house in Compton Avenue, I believe.'

That is so typical of snobby Bella, though as she's a home stylist I suppose she's only showing a professional interest in the Burnses' pile of bricks. Still, I'm seriously tempted to freak her out by pretending that Duncan and Fiona Burns made their money by dealing in illegal drugs or dodgy diamonds, but she might swerve off the road with shock and pin some innocent dog walker against a bus stop, so I decide to keep quiet and just say, 'It's early days. We haven't even been on a proper date yet.'

'But he's been texting you loads, hasn't he?' Lucy says. 'So he must be keen.'

It's true that Frazer Burns has been texting me whilst he's been in Northumberland visiting rellies for New Year. Unfortunately, whilst Josh has been sending texts to Lucy telling her he misses her and comparing her to dappled moonlight, FB has been informing me that Northumberland has five times as many sheep as people, that he's worked out the unleaded petrol consumption of his father's BMW on the trip up north without using the on- board computer, and is wondering whether they will achieve the same stunning statistics on the journey home today. There's been no Wish you were here or even a polite kiss on the end of any of them. I thought he might at least have mentioned the Christmas Day snog on the street, or the fact that he texted me later that evening reminding me I've promised to go on a proper date with him, not a hanging-around-the-shops-type date. I'm now seriously wondering whether he'd overdone it with the festive chocolate liqueurs and was a bit squiffy when we snogged. I couldn't smell booze on his breath, but then I was so gobsmacked by having my gob kissed and FB scoring 5 out of 5 on my Snogability Scale, I probably wouldn't have noticed even if he'd been gargling with whisky and smoking magic cigarettes.

Bella turns the Beast Car into Forge Road and pulls up outside Sorrel's house.

All the other drives in front of the row of modern terrace houses have neat gardens with one, maybe two cars parked on the drive. The Callenders' house, number 5, looks like a cross between an allotment and a scrap yard, with pots of sprouting potato tops and carrot fronds fighting for space with kids' bikes, a strange sundial made out of bits of metal and the enormous black ex-funeral car Yolanda, Sorrel's mother drives.

And now something new has appeared in the front garden.

An old white caravan so tiny, it looks like an egg on wheels has been laid outside the living-room window.

After Sorrel and I caught her older sister, Jasmine, with Warren Cumberbatch (a lanky louse of a lad who Sorrel fancied) at It on the bottom bunk in Sorrel's bedroom, Yolanda promised Sorrel her own room. But until the housing association can find a bigger house for five children, two adults, a cat, huge numbers of jam jars with sprouting seeds and a large collection of wind chimes and crystals on strings, Sorrel's bedroom is a caravan on the drive.

'What on earth must the neighbours think?' The Neat Freak shrieks as we walk towards it. She's probably freaked at the thought of living next door to someone who has no interest in paint charts and coordinated soft furnishings. 'It makes the place look like some sort of Third World encampment.'

The top half of the caravan door flies open and Sorrel leans out.

'Some people in the Third World would regard this as luxury, Mrs M, given the fact they sleep in sewers or on rubbish tips,' she says pointedly, but with a smile.

Luce and I rush towards her as Sorrel opens the bottom door, climbs down a couple of steps and throws her arms around us. It's so good to have her back from her Christmas trip to Barbados where she's been visiting her dad, Desmond. She looks fantastico. Relaxed, refreshed and totally different to the girl who ran away and lived for a week on the streets and in a borrowed flat with dodgy men last December.

'Did you have a good time?' Bella asks, trying to peer into the caravan to see what decorating disasters are lurking within. 'Did everything work out? Was your father well?'

'It was wonderful, Mrs. M. Thanks for everything. Did Electra's bag and all the other stuff cover the air fare?'

To pay for the ticket to Barbados, Bella sold my Bag of Beauty - a Chloé total bling bag I'd been given by The Kipper, Dad's evil ex-girlfriend - on eBay, along with some unwanted designer stuff of hers and old clothes of Lucy's and her older brothers, James and Michael.

'There's actually a little money left over,' Bella says. 'Any thoughts on what you'd like to do with it?'

I'm about to suggest a seriously slap-up meat-themed meal in town to welcome Sorrel back, when she says, 'I'd like it to go to some environmental scheme. Plant a tree or recycle a bottle or something.'

'I'll come up with some ideas,' Bella says, taking over yet again.

'Thanks,' Sorrel says, as we amble back towards the Beast Car. 'Oh, and Mum said she'll run the girls home after lunch.'

Bella looks as alarmed as a woman with a serious Botox- frozen forehead can manage. Clearly the thought of the Gothmobile pulling into the drive of Foxgloves, the Malones' executive home on a private road surrounded by other snobby neighbours, freaks her out.

'Oh, I'm more than happy to come back,' Bella says briskly, climbing in. 'I know how your mother hates using the car for unnecessary journeys. Save the planet and all that.' Clearly Bella has forgotten she drives a gas-guzzling Beast Car just to get her morning paper.

'It's fine,' Sorrel says. 'Mum's had it converted to run on pig poo.'

'Pig poo?' Bella squeaks, her blonde highlights quivering. 'That car is running on animal excrement?'

With a totally straight face, Sorrel nods. 'You'd never know. Well, not once the car's been running for a bit. Before that a really farty smell comes out of the exhaust.'

I'm in serious danger of wetting myself with laughter as Bella slams the car door and speeds away.

Giggling, the three of us go into the caravan.

Outside, the mobile bedroom might look a bit rough, but inside it's absolutely gorge.

By the window is a little table, which Sorrel's set up with her laptop, pots of pens and pencils and a burning incense stick. Either side of the table are long seats piled with brightly coloured cushions. There's a tiny kitchen area with a shiny new kettle, rows of jam jars with tea, coffee and sugar labelled on them, and, at the other end, a couple of bunk beds with red-and-white-checked duvets draped on top, the same material as the curtains at the windows.

'Oh, Sorrel, it's fab,' Luce says as we look around. 'You must be thrilled.'

Not just sewer-dwellers would love to live here. I would too. Being detached, I wouldn't have to listen to The Little Runt, aka my nine-year-old brother, Jack, whining on about Arsenal losing, or find bunny poo squished between my toes because he's brought Theo, his rabbit, into the kitchen. I could cook pizzas and chips at midnight without a parental becoming all sniffy, and leave the washing up to fester for weeks without stress. But best of all, it would keep me and the sproglet apart when Mum has the baby at the beginning of June. I wouldn't have to listen to it yell, or cope with nappy smells or sit and eat my tea whilst it voms up pureed beef and carrots next to me.

I'm dreading it.

However hard I try to think about gloriously shallow things, such as hot dates with FB, what I'm going to spend my Christmas money on and whether I can get away with keeping the plum nail varnish I'm wearing today when I go back to school tomorrow, the fact that my mother is going to have a baby is becoming impossible to ignore, and not just because she's devouring jars of pickled onions, getting huge before my very eyes and her boobs are no longer Mighty Mammaries but Monster Mammaries, but because Mum's boyfriend, Phil, has this really disgusting habit of going up to her every morning, putting his hand on her tummy and saying, 'How's it cooking, Ellie?' which is gross when I'm trying to force down a bowl of Shreddies or a Strawberry Pop-Tart before school.

'Can I move in when the sprog arrives?' I ask Sorrel, only half joking. 'Not for ever, just until I'm old enough to leave home without being hauled back.'

I'm fifteen in July, so I reckon I'd have to share a chemical toilet and a bunk bed for about a year and a half, which isn't bad when you consider the alternative.

'Still got pre-natal depression?' Sorrel asks, holding up a tin of hot chocolate.

I'd emailed her in Barbados to tell her about FB and me, and about Mum's Christmas lunch announcement that there wasn't just a turkey in the oven, but a baby too. At the time I was more excited about the snog than worried about the sprog, but now the novelty of the snog has worn off and the grim reality of the sproglet has set in, I'm the one with the baby blues.

'It was the pits when Mum and Ray had the twins and I was eleven.' Sorrel spoons brown powder into three mugs I recognize from The Bay Tree, the organic vegan café Yolanda runs. 'Of course, The Loony Lentil had to be all earthy and have a home birth so I was totally freaked when I went to the loo and saw a whole load of red slime in the bath. I thought someone had been murdered.'

'Too much info,' I say, starting to conjure up dreadful pictures of graphic gynaecological things happening in the bathroom of 14 Mortimer Road. 'Tell us all about Barbados.'

Sorrel brings the mugs of hot chocolate over to the table and slides into the seat across from me and Luce.

'It was amazing,' she says dreamily. 'From the moment I stepped off the plane I felt totally at home. Everyone I met was so cool. I'll download some photies later for you to gawp at.'

'It must have been great to spend Christmas somewhere hot,' I say. Now I've stopped gazing at the soft furnishings, I realize Sorrel's caravan is actually an igloo in disguise. I'm shivering even though underneath my coat I've got FB's soft navy jumper on, the one he gave me to wear on Christmas Day. To be honest, after nine days in my room and on my bod, it's ponging of a rather strange mix of deodorant, dust and perfume rather than smelling of FB and his posh house, but just the feel of it reminds me of what happened between us and sends shivers down my spine, which probably isn't helping the whole body-temp situation.

'Doesn't this place have any heat?'

'I'd rather not use the heater,' Sorrel says primly. 'Not if I can help it.'

Luce and I exchange glances. Sorrel had said things were tough what with Ray, her sort-of-but-not-yet-legal stepfather losing his job at the camera shop, but I had no idea they're so broke they're risking hypothermia.

'If things are that bad, you could use the extra bag money for the heating,' Lucy suggests. 'And you might be rehoused soon.'

That would be fantastico for both of us. The Callenders would have a bigger pad, and I could have Sorrel's cast-off caravan. We don't actually have a drive on which to park it, so I'd have to live on the street, which thinking about it is even better as I'd be further away from the squitting sproglet and FB could come round at all times of the day and night without anyone knowing.

Sorrel stares at us and then giggles.

'Thanks, Luce, but it's not because of the money I'm on heating rations. I'm just trying to do my bit to conserve energy and save the planet.'

Now it's our turn to stare at our bezzie. Despite being brought up by the sort of rampant eco-warrior who goes out and slaps Gas Guzzler stickers on 4x4s and people carriers, Sorrel has never shown the slightest interest in saving the planet. In fact, sometimes she walks around her house switching lights on, just to wind Yolanda up. 'Did I hear right?' I say. 'Did the words save the planet actually come out of your mouth? Have you turned from teenager into greenager?'

'Yeah,' Sorrel nods, laughing. 'Before, when Mum droned on about saving the environment I'd look at places round here and think, Why would I want to save Eastwood Circle?' She takes a sip of her hot chocolate. 'It's pants.'

'It is pretty ugly,' Luce agrees. 'But I like Top Shop. Oh, and Superdrug. I'd be lost without Superdrug especially when they do three-for-two deals on L'Oréal and Lil-lets--'

'What I mean,' Sorrel says, stopping Luce before she can add more items to her shopping list of cut-price toiletries, 'is that when I went to the Caribbean and saw how gorge it is, it made me realize the planet is bigger than just my usual world of concrete shopping centres and school, and that I need to do something to save it.'

'Did you get any sleep on the plane?' I ask, wondering if an overnight flight has scrambled Sorrel's brain.

Sorrel gets up and puts her hands on her hips. I think she'd probably like to start pacing, but there's not much room to pace in a tiny caravan. You might get two strides in before you'd hit the window at the other end and have to turn round again.

'You think I'm nuts, don't you?' she demands, sounding like the old sarky non-green Sorrel we know and love. 'Can't you see, we're killing our planet with selfishness! If I told you your grandchildren may never get to see a fresh lobster because the sea is so warm they'll come out ready cooked, what would you think about that?'

Good heavens! Sorrel's already got me being a grandmother and showing my grandchildren seafood when I haven't even been on a date with FB yet! And will I still be with FB by the time I'm a grandmother? I can't seriously imagine going out with anyone other than FB ever, but I can't imagine being an old wrinkly either.

'Electra?' Sorrel interrupts my thoughts just as I'm wondering whether I'll look more like bony Nana Pat or buxom Grandma Stafford when I'm ancient. 'What are your thoughts on all this?'

'What are my children called?' I ask. Mum keeps asking me whether I have any ideas about baby names as I've always banged on about how I hate my name and how being called after the self-catering apartments in Faliraki where Mum and Dad spent their honeymoon was totally inappropriate as I'm so not a Greek girl with my wide-as-a-satellite-dish pasty face, mousy long hair and mottled salami limbs. I've told her that as far as I'm concerned, they can call the sprog Ermintrude or Zebedee and to leave me out of name-game.

'Your children?' Sorrel asks. 'What's that got to do with anything?'

'You said my grandchildren might never get to see a lobster, so I must have children. I was just wondering what they were called.'

'Josh and I like Jemima for a girl or Jeremy for a boy,' Luce says dreamily as she fingers Josh's leather bracelet, which is wrapped twice around her slim wrist.

'Jeremy!' I say, freaked at both Lucy's choice of name and the fact that even though they've been going out for less than a month and he's been away for a week of that, her and Josh have been having discussions about naming their as- yet-to-be-conceived kids. 'You can't call a kid Jeremy!'

'It's after his father,' Luce says primly, winning the argument as clearly I can't claim that calling your son after your dead dad is a bad thing, unless of course your father was called Adolf.

'You two can be so shallow!' Sorrel gasps. 'I'm serious! Our generation has to do something or there'll be nothing left in the future. It's not just Mum who says this, Joz does too.'

'Joz?' I ask. 'Who's Joz?'

Sorrel twists one of her long black braids around her finger and examines the end. 'Daphne's son.'

'And Daphne is?' I say leaning towards Sorrel. This sudden revealing of the name Joz coupled with my bezzie's sheepish expression has made me ueber suspicious that we haven't been told the most exciting part of Sorrel's trip, and that she's hanging back on the holiday romance goss.

'Daphne's Dad's girlfriend. I didn't know he had one until I went over there 'cause he never mentioned her, but it turns out he's been living with her for years. She runs a seashell shop, Daphne's Designs, next to Dad's art studio. Joz takes tourists out on jet ski trips to look for turtles and things. He's really into marine conservation. He told me about the ready-cooked lobster.'

I knew it! There had to be a reason why Sorrel has gone from eco-wrecker to eco-warrior in the space of two weeks, and it was so obviously testosterone-induced. It's like when I started to spout Shakespeare at every turn. I didn't really like Billy Boy's plays, but I thought it might impress a Spanish Lurve God called Javier Antonio Garcia, aka Jags. It didn't: Jags turned out to be a Sleaze Bag from Slough, and now I can't remember a single line from any of the bearded Bard's stuff, somewhat of a worry given that I'm supposed to be doing The Taming of the Shrew for GCSE English lit.

I narrow my eyes, turn my Snogdar on to full power and direct it straight at Sorrel.

'Have you had a festive romance with this Joz?' I ask. 'Have you been on a jet ski discussing your future offspring's lobster lunches with him and snogging in the surf?'

'You have a one-track mind,' Sorrel says, getting up and digging around in her opened suitcase, which is lying on the bottom bunk. 'There's nothing going on with me and Joz other than the fact we both feel strongly about the environment.'

'If The Jozster is really into saving the planet, shouldn't he be using a rowing boat rather than a jet ski?' I point out.

Sorrel ignores my eco-observation. 'Here, these are for you.'

She hands Luce and me each a tiny blue tissue-paper package on which someone has pencilled L and E. When I open mine, nestling inside is a beautiful pair of dangly earrings made out of a cluster of tiny pink and white shells.

'They're gorgeous, Sorrel,' Luce says as she holds hers up to her ears, each one made out of a small creamy scallop- shaped shell. 'Thanks so much.'

'They're brill,' I say, getting up to give her a hug. 'Thanks.'

'Daph gets those from the beach and makes them into earrings, but Joz says if the seas get too hot because of global warming, there'll be no shells.'

The thought of no more pretty shell earrings is gutting, I must admit, though not as gutting as for Daphne who'll no longer have any shells to sell, which is uno major problemo if you own a shell shop.

'So there was defo no hot date with Joz the Jet Skier?' I ask. 'No frolicking in the surf or snogging in the sand?'

'Have you and Freak Boy sorted out your first date yet?' Sorrel asks, clearly trying to change the subject. 'Where's it going to be? Sitting on a station platform trainspotting or is he going to really push the boat out and take you to the airport to count jumbo jets?'

Despite my insistence that FB is more Fit Boy than Freak Boy nowadays, Sorrel still thinks he's majorly weird.

'None of the above,' I say, throwing Sorrel a sarky look.

'He hasn't mentioned a date. I don't know what's going on at the mo.'

'Perhaps he's playing hard to get,' Sorrel suggests. 'Or maybe he's met some northern girl and had a holiday romance and gone off you.'

'Perhaps he had a midnight snog on New Year's Eve and one thing's led to another,' Luce adds.

'Are you two deliberately trying to do my head in?' I say, slightly more snappily than I intended. 'I'm stressed enough already!'

There's a knock on the caravan door, but no one appears until Sorrel shouts, 'Come in!' and Yolanda's head appears over the half-door.

I am dead impressed. Sorrel has her mum well trained. My mother has no idea of teenage room etiquette. She thinks that if you knock you can then come straight in; in other words, the knock is just an alert that she's about to barge in rather than a request to enter.

'Hello, girls!' Yolanda's white smile stretches across her face. She's wearing one of her trademark brightly coloured scarves around her head, her skinny dreads bursting over the top like a hairy black chrysanthemum.

'Lovely to see you.'

'Hi!' Luce and I chorus back.

'Did you have a good Christmas, Mrs. C?' I ask.

'Well, we missed Sorrel, but we did our best to give everyone a good time,' Yolanda says, her face clouding over at the thought of festivities without one of her brood. 'But what I really want to know is, how is your ma, Electra? Sorrel tells me she's expecting a little one. You must be thrilled.'

'She isn't,' Luce says.

'And are you hoping for a little sister or brother?' Yolanda asks.

'She's hoping for a puppy,' Sorrel giggles, which is true.

'And all is well, she's fine?'

'She had a scan and it seems to be,' I say, remembering the blurry photo of what looked like a tadpole in a whirlpool that's stuck on the side of our fridge under a letter-B fridge magnet.

'I'd love another baby,' Yolanda sighs. 'A little girl called Saffron or a boy called Bay.'

'Mum, you cannot be serious!' Sorrel shrieks.

'Maybe I already have my hands full.' Yolanda sighs.

A dark-skinned lump of a girl with braces and specs appears at the door. It's Senna, Sorrel's nine-year-old sister. 'Lunch is ready,' she scowls, before disappearing.

'Would you girls like your lunch out here so you can carry on gossiping?' Yolanda asks. 'It's just some spicy chickpea patties and red cabbage salad.'

'Yes please, Mum!' Sorrel says, smiling. 'That would be great.'

Pre-Barbados Sorrel would have turned her nose up at what she calls fart-food, but now she looks delighted at the sound of the menu. I'm slightly worried that I won't be able to concentrate on my history assignment this afternoon for continuously raising my bum off the chair to deal with the after-effects of curried chickpeas.

'Can one of you just come and help me bring it over?' Yolanda asks.

'I'll go,' I say, just as my phone vibrates in my pocket.

I fish it out, look at the screen and open the text.

I can't get my breath. I'm flapping my arms around and I think my heart is about to explode it's beating so fast.

'Electra!' Yolanda cries. 'What's wrong? What is it?'

I wave my moby in the air, still gasping.

Sorrel grabs it.

'It's a text from FB,' she says. 'That's what's set her off.'

'Oh, no!' Luce cries. 'Has he snogged a northern girl after all?'

'Doesn't look like it,' Sorrel says. 'It says: "Back. Missed You. What about that date then?" '