'It's me! I've just done the school run! Where are you? Phone me and I'll call you straight back.'

It was Lucy. Or, rather, it had been Lucy, phoning from Hong Kong. Hours and hours ago. It was now gone six and over the seas and far away Lucy would be fast asleep. In fact, it was already Tuesday for her. If Petra waited until eleven, she'd catch Lucy at breakfast.

The conversation started as it always did: with brief marvelling at the clarity of the phone line and how much time had pa.s.sed since they last spoke.

'I miss you,' Petra said. 'What are you having for breakfast?'

'Fruit salad,' Lucy laughed. 'Miss you too. I did phone yesterday. What's up?'

'Well, I feel OK now because I had a productive day at the studio. But I woke up feeling c.r.a.p because I used up my weekend visiting my parents.'

'It's not Christmas,' Lucy said.

'I know.'

'I thought we'd decided you'd only visit at Christmas?'

'I know. I don't know why I did it, really.'

'How were they?'

Petra paused. 'They're both always so preoccupied. I just feel inconsequential.'

'You are far from it,' Lucy said, almost sternly.

'Thank you,' Petra said. She paused because she wanted Lucy to continue.

'You're the strongest person I know,' Lucy said. 'All your achievements are your own. G.o.d, it's not as if your parents gave you a leg-up, a foot in the door or even a pat on the back. You've always managed to stride out by yourself. And look at your success.' She said it with triumph. 'Does that help?' she added.

'Ish,' said Petra.

'Don't let them upset you,' Lucy said, 'because of course they don't mean to. They're not bad people they're just, well, c.r.a.p parents.'

Petra paused.

'You don't really need them,' Lucy said.

'But sometimes I want them,' Petra said.

'Everyone needs a sense of family,' Lucy said, 'in every sense of the word. You don't quite have that and that's tough. How are you sleeping?'

'Not good,' Petra said. 'I've been waking up knackered. I think I must be sleepwalking a lot.'

'How is Rob?' Lucy asked.

Petra paused. She was acutely aware that she never paused when Eric or Gina or Kitty asked the question. She always jumped to his defence; blowing his trumpet and singing his praises. But with her oldest friend, such exaggeration was pointless. Honesty though, required greater effort. 'Fine.'

'Fine?'

'Ish,' Petra qualified.

'I don't like the sound of "ish",' said Lucy, wishing she was in the UK, wishing she knew Rob better because her first impression of him hadn't painted her a particularly pleasing picture.

'I'm not quite sure where I stand and I feel I should after ten months,' Petra said. 'After all, I've made it my mission to ensure that he wants for nothing from me. s.e.x. Support. Affection. s.p.a.ce.'

'You give,' Lucy defined, 'but what do you get? Does he actually warrant all the effort you bestow?'

'I wish he'd ask me to be with him you know, move in, or something,' Petra said, pointedly ignoring Lucy's question. 'I wish he'd just ask. I'd like to feel that he loves me enough to at least ask.'

On the other side of the Pacific, Lucy had closed her eyes and frowned. Love shouldn't be such an effort. But she didn't think love was the point she suspected it was self-esteem. Petra will stick with Rob, Lucy thought, because Petra loathes the thought of splitting up. Petra wants to feel loved regardless of whether the object of her affection is actually worthy of hers.

'It's his birthday on Friday,' Petra said, aware of Lucy's silence and changing tack because of it. 'I won't see him until then. He's too busy. He says.'

'Will you be going out to celebrate?' Lucy asked, her tone light. If she couldn't physically be there to pick up the pieces, then she couldn't very well dish out the home truths.

'Yes. Somewhere in town, I guess. He hasn't decided. He's not really into birthdays.'

'Don't take that personally,' Lucy said.

'I've bought him a leather doc.u.ment case. Cost a bomb. And I might let myself into his flat beforehand,' Petra told her. 'You know prepare it for later.'

'What, balloons and banners?'

'And rose petals!' Petra enthused, missing Lucy's sarcasm.

'He's a lucky boy,' said Lucy and she really meant it.

'Thanks, Luce,' Petra said.

'Call me,' Lucy said, with a touch of urgency, 'whenever. Seriously. Any time.'

Chapter Nine.

Perhaps Rob's mobile was on silent. But he'd said he'd be working late, so Petra wondered why on earth she was trying to distract him with phone calls anyway.

'Oh well,' she said, 'may as well go to bed.' But first she went from room to room, collecting her damaged paperbacks which had been splayed over the radiators all evening to dry. She took them all into the sitting room. In drying, they had fanned themselves out, some almost 360 degrees, like drab versions of Christmas paper lanterns which take form when folded in on themselves. She scouted the room for heavy items to place on them. Some she put into piles, placing chair legs on top. Her Tony Parsons paperbacks she lay side by side underneath the television set and she set her John Irving collection upright, against the skirting board, wedging the sofa against them.

There were still another sixteen paperbacks remaining, fanned out like Elizabethan ruffs, but all the heavy items in the sitting room had been put to good use. Petra checked her mobile. It was still blank. Gathering the books, she took them into her bedroom and laid them in a shambolic pile on the pew while she upturned her mattress and jostled it off the bed frame and up against the wall.

On her bed base, she put Barbara Trapido shoulder to shoulder with Nick Hornby and was just about to add Hilary Mantel to make an interesting threesome when she was distracted. Near the head of the bed and over to one side was a black velvet pouch with a thin gold silken cord. Petra leant across Nick Hornby, nudging Barbara Trapido out of the way as she did so, and took the pouch. She didn't open it; initially she just brushed the velvet against her cheek, her lips, as she sat cross-legged on the edge of the bed.

After a while, she slipped out the knot in the cord and eased open the neck of the pouch. With a little shake, she tipped out the contents. A white cotton handkerchief wrapped carefully around something hard. As she began, slowly, to unfurl the handkerchief, taking time to trace the embroidered 'P', she was about to detour in her mind's eye back to the John Lewis department store, to shopping with her mother, to the time when her mother bought her this handkerchief, a time when her mother wore glamorous red shoes and didn't have alfalfa for hair but Petra pulled herself back from that memory because there was somewhere else she'd rather be. The handkerchief was now open and there, glinting and breathtakingly beautiful, lay Petra's tanzanite. The size and gloss of a quail's egg: 39.43 carats of it, beautifully worked into a stunning pear cut with a dazzling array of light-reflecting facets. Internally flawless; brilliantly blue with a seductive wink of violet too.

On her bed, she cupped her hand as a cradle for the gem. It felt warm and rock-solidly rea.s.suring to hold while she travelled back seventeen years, back to the day she first heard about tanzanite.

'Mrs McNeil?' Petra called through the letter-box. 'Lillian? Hullo? It's me, it's Petra.'

The door opened less than ajar. 'So it is,' said Lillian McNeil. 'Come on in, dear.' And she opened the door precisely wide enough for Petra to sidle her slim, fifteen-year-old body through sideways.

'Oh, Mrs McNeil,' Petra said softly, sadly, raising her hand gently to the bruising around the lady's right eye. 'It looks worse today than the day before yesterday.'

Mrs McNeil swept at the air as if her black eye looked far worse than it felt. 'The good news is they caught the little scamps.'

'Lock them up and throw the key away,' Petra said angrily.

'There was only a few bob in my purse. And my watch was cheap as chips it just looked fancy. And my eye well, I fell, you see. That part was just bad luck. They didn't actually touch me at all.'

'I'd quite like to swear now.'

'Absolutely not. Swearing does not become you, Petra Flint.'

'I'm just so angry.'

'Let it pa.s.s, Petra. If I have you must.'

'Well, I bought you something Walnut Whips. I bought you a packet of milk ones and look, new plain ones too.'

Lillian's eyes sparkled rather than watered now. 'You'll have to help me eat them.'

'OK! Oh, and I brought you this. I took it out on my library card.' She handed Mrs McNeil an audio-ca.s.sette of Pride and Prejudice. 'I thought if your eye was sore. I thought if you didn't feel like reading. I know how you love your books.'

'Bless you, little Miss Flint.'

Petra shrugged off the compliment. 'Let's eat the Walnut Whips,' she said and she let Mrs McNeil choose between the plain and milk chocolate packets. 'Shall I make tea, too?'

'No, dear,' Lillian said, 'I'll do that. Young people just don't have the knack.'

'We're not taught properly,' Petra agreed. 'Before I met you, I'd never seen loose tea, just bags.'

While Mrs McNeil was pottering and clattering around the kitchenette, Petra browsed the room. She'd been visiting Mrs McNeil for nearly two terms. In fact, the summer holidays had just started, but it didn't occur to Petra not to visit. It might be the school holidays but it wasn't as if she was going on a family holiday this year. That in itself would be a contradiction in terms. It couldn't be much of a holiday if there wasn't much of a family. And anyway, there was something really nice about visiting out of school hours and not having the time restraints of double maths or netball or pottery at Milton College to rush away for. And, though there had been the unpleasant incident with Mrs McNeil's bag at the bus stop the previous week, Petra would have visited Mrs McNeil today anyway: she was her companion, not her duty.

That room. That lovely room; walls awash with art of all description, surfaces heaving under the breadth of possessions accrued over decades, even the floor s.p.a.ce reduced by that veritable library of diverse tomes. How many times had Petra been in this room? And there was still so much to look at. She loved all the trinkets and keepsakes from a history of visits to a wealth of countries and cultures; the ant.i.thesis of just the two statement pieces of Lladro that her parents had bought to embellish the mantelpiece, one of which had gone to Watford with her father. Most of all Petra loved Mrs McNeil's pictures, some of which were prints, others originals in oil or water-colour or pastel or charcoal; some representative, others abstract, some framed, others tacked up with drawing pins. She was lost in thought, gazing at a vibrant oil painting, when Lillian came in with the tea.

'Mrs McNeil,' Petra said slowly, not turning around, still transfixed by the painting, 'I've just got it!'

'You shouldn't use the word "got", you know,' said Lillian, 'or "get". It's lazy.'

'I mean, I've just figured it out!' Petra qualified, her eyes still on the painting. Slowly, she turned, her face flushed with excitement. She walked across the room, towards Lillian and went to the watercolour of Kilimanjaro which hung by the front door and which she'd admired on her first visit. 'This is Mount Kilimanjaro,' she said, then walked over to the colourful abstract in oils which had so mesmerized her. 'And this is, too!'

Lillian McNeil regarded her, steadily but expressionless. It didn't matter to Petra.

'All these times I've been here, in your home, I thought this painting was just a gorgeous colourful explosion of colours and shapes. You know, abstract art. I thought maybe it symbolized fire and light and atmosphere a bit like Joseph Mallord William Turner who we've been doing in art.' Petra stared at the picture. 'But I didn't realize it was real,' she whispered. 'Hang on I've lost it!' She fell silent. 'Here!' She traced her finger over the coloured shapes to denote the form. 'It's real, isn't it it's Kilimanjaro. But to me, it looks like Kilimanjaro is on fire!'

'It is,' Lillian said softly, a little sadly. She paused. Then she straightened herself and smiled. 'That painting was done over twenty-five years ago, Petra, and it appears you and I and one other, who is no longer with us are the only people to recognize its true subject matter. Most people think it's a colourful pastiche of Clyfford Still.'

'Who?'

'You'll learn. In art.'

'But it isn't.'

'No, it isn't. It's by Hector McNeil. My late husband. He painted that. He painted it for me. We loved Tanzania. We lived there, happily, with Kili as our magnificent backdrop. More than a backdrop. That mountain was our everything.'

Instinctively, Petra went over to the chair in which she always sat and nodded gratefully as Lillian poured the tea. She placed the cup and saucer carefully on her knee and sipped daintily. She was sure such manners were the outcome of taking one's tea in a bone-china cup and saucer. At home, there were only clunky Denby mugs.

'Is the fire real or abstract?' Petra asked. 'Did the mountain really catch fire, when you were there?'

Lillian poured tea for herself, settled into her chair. 'Legend has it that a great fire struck the mountain and that is what Hector's painting celebrates. Fire needn't necessarily destroy, Petra dear. Fire can reveal. Fire can create. Fire was the reason we came to be in Tanzania.'

Though Petra meant to sip, in her excitement it turned into a slurp. 'Sorry,' she said.

'Actually, the story starts a fair few years before the fire, Petra,' Lillian began, '585 million years ago to be precise, when the continents collided in the pan-African event and caused a geological phenomenon. There, you can knock your geography teacher for six when you go back to school.'

'What was the phenomenon?'

'A most beautiful and rare gemstone was born.'

Petra's glance ricocheted from the watercolour of Kilimanjaro by the door, to the vibrant oil of the mountain on fire across the room.

'Have you heard of the Masai?' Lillian asked her.

'Of course,' said Petra, 'we did them in geography last term. We watched a video and our teacher brought in real Masai beads. I wore the bangle all lesson.'

'A Masai legend tells of how a lightning bolt struck Kilimanjaro, setting the mountain ablaze and creating a magic fire in the sky. When the flames died down, glistening amongst the ash were stones of the most amazing array of blues: royal blue, midnight blue, indigo, periwinkle, lavender, blue-violet, violet-blue, pure violet. You see, the conditions had to be right those millions of years ago for the gem to be born and then, many millennia later, conditions had to be right for its existence to be revealed.'

'Wow,' said Petra. 'Is it a sort of diamond then?'

'It's actually a thousand times rarer than diamond, Petra. And that's a fact.'

'Sapphire?'

'No it is the colour sapphire wishes it could be.'

'What is it?'

'It is tanzanite.'

'Tanzanite?' The word was lovely on the tongue.

'And in just a few decades or so, there will be no more tanzanite. At all. It will be gone.'