The high whine of the jet engine dropped a little as the plane hit its cruising height and levelled out. Lindsay pressed a button in the armrest and exchanged the operatic aria in her headphones for contemporary Irish music. At least flying Aer Lingus meant there was a decent choice of in-flight music, she thought. And the music was the perfect distraction to avoid having to think about why she had agreed to a marathon journey back to London, changing at Dublin, in the charmless company of Sandra Bloom.

Ten minutes after Lindsay had made it back home, the dogged private eye had rung the doorbell. Lindsay had tried to ignore it, continuing on her journey to the fridge for a cold beer, but Mutton refused to play. He ran to the front door, snuffling eagerly round the edges, then barking loudly, tail wagging as he scented his newest friend. He turned to look expectantly at Lindsay, uncapping her beer and ostentatiously ignoring the dog. He gave a soft whimper then turned back to the door, outlining its edges with anxious snorts and anguished yelps.

"All right," Lindsay sighed. She took a long swig of beer, then crossed to the door. She yanked it open and immediately said, "I told you no, and I meant it."

Sandra Bloom nodded agreement. "I know. But Ms. Miller is adamant that you're the only person who can help her. She stressed that she wants you to come not only because of your investigative skills but also because you're a friend and that means she can trust you with things she'd be wary of explaining to a stranger."

Lindsay cast her eyes upwards. "Emotional blackmail now, is it? I suppose you'd better come in. The neighbours think we lower the tone enough as it is without having private eyes leaning on the doorbell."

Sandra Bloom had been an investigator for long enough not to care how ungracious an invitation might be as long as it was forthcoming. She followed Lindsay inside and took in a living area with polished wood-block floors, dark squashy sofas, and brilliantly coloured Georgia O'Keefe prints splashed across white walls. She decided not to comment on its attractiveness, knowing instinctively her target would dismiss it as merely another ploy. "I realise you feel pressured," she said as Lindsay threw herself down on the nearest sofa, scowling.

"Good."

"But Ms. Miller is in a very vulnerable emotional state. Her lover - "

"Former lover," Lindsay interrupted.

"Her lover until very recently," Sandra Bloom corrected her precisely, "has been murdered in a particularly calculated and cold-blooded way. She's on her own in a strange city, thousands of miles from her friends. And as if that isn't enough, she's a suspect in the murder inquiry. And you're the only person she thinks can help her."

"But I'm not," Lindsay protested. "What has she told you about me?"

"Very little. She did say that although you weren't a detective, you'd solved murders before."

Lindsay took another long pull at her bottle of beer. "Look," she said. "I'm a journalist by trade. I don't even do that any more. I teach kids how to be journalists because I realised I couldn't do the job any more. It was costing me too much to burst into people's lives and turn them upside down. Yes, I got caught up in murder investigations a couple of times and managed to uncover some stuff that the police didn't. But none of that makes me competent to sort out Meredith's problems."

"You're probably right," Sandra Bloom said sympathetically. "It takes a lot of skill and experience to be a good detective. You might have the rudiments of the skills, but you certainly haven't got the experience. Frankly, I think Meredith Miller would be better off hiring almost any private investigator in London. That's what I told her lawyer. But Ms. Miller wasn't having any. It was Lindsay Gordon or nobody."

Lindsay's scowl deepened. "I told you, emotional blackmail doesn't work."

"Fair enough." Sandra Bloom's smile was placatory. "And I fully appreciate why you don't want to get involved. It can get hairy out there on the streets. You don't want to be out on the front line unless you really know how to handle yourself. No, better Ms. Miller has nobody out there batting for her than she has somebody who doesn't know what the hell to do next."

The smile was starting to make Lindsay feel patronised rather than soothed. "I didn't say I was totally clueless," she muttered.

"Of course not," Sandra continued blithely. "But you said yourself, you're a long way off being a pro. But you appreciate I had to come and double check." She took a step toward the front door. "I can go back now with a clear conscience. Once she realises that she can't count on having an investigator who's one of her closest friends, I know she'll settle for a regular firm of private investigators. I know a couple we can recommend to her. Thanks for your time, anyway." Another step toward the door. "I'll tell Ms. Miller that you fully sympathise, but you're unable to help."

Lindsay dropped her empty bottle on the floor with a clunk. She sighed. "OK. You win. I'll come back. You can stay here tonight, and first thing tomorrow, we'll sort out a flight."

Sandra Bloom's smile quirked upwards at one corner. It was the only sign that she'd succeeded in a carefully worked-out plan. "Not quite," she said. "I've got reservations for an overnight flight."

Lindsay looked at her watch. "Tonight? No chance. I've got to discuss this with my partner, I've got to pack, I've got arrangements to cancel..."

"And Ms. Miller could be under arrest by morning."

Lindsay stood up and glowered at Sandra Bloom. "Have you ever met my partner? Sophie Hartley?"

Sandra Bloom shook her head, puzzled. "Why? Should I have?"

"I think the two of you took the same guilt-tripping course," Lindsay growled, picking up the bottle and stomping through to the kitchen.

Five hours later, she was in flight. Because college had broken up for the summer, she had no teaching burden to rearrange. Writing the book could wait; she'd reached the point where any distraction was welcome. It had taken less than half an hour to pack the assortment of light and heavy clothes an English summer normally demands. Lindsay's attempts to contact Sophie had taken rather longer since Sod's Law - anything that can go wrong will go wrong - was the only exception to itself, operating like clockwork as usual. Inevitably, Sophie and her cronies hadn't been in their usual restaurant, so Lindsay hadn't been able to speak to her lover. She'd ended up leaving a written explanation stuck to the tin of camomile tea that she knew Sophie would hit as soon as she came home. Hopefully, Sophie wouldn't be too upset, given that their own summer trip to the UK was due to start in a week's time anyway.

As the night slipped away under the plane's wings, Lindsay wondered what she would find at the end of her journey. One thing was certain. Her own mourning had to go on hold if she was to be any use to Meredith at all. And in spite of her initial resistance to Sandra Bloom, Lindsay wanted to do what she could for Meredith. She'd always had a soft spot for her, not least because of Meredith's response to her techno-fear.

It had happened after her last brush with murder. She and Sophie had been telling the story to Meredith and Penny one weekend when the four had been camping down at Big Sur. By lantern light, Sophie had revealed how, without her computer expertise, Lindsay would never have uncovered the truth behind the death of trade union boss Tom Jack. Both Meredith and Penny had been open-mouthed with astonishment to discover that someone who worked in the communications industry was a virtual electronic illiterate.

"Doesn't make me a bad person," Lindsay had mumbled uncomfortably.

The others hooted with laughter at her discomfiture. "You don't have to be a nerd to know a bit from a byte," Meredith told her. "Hey, it's only scary because you don't understand it."

"I've tried to teach her," Sophie said.

Meredith snorted. "That's like husbands teaching their wives to drive. Never try to teach your beloved anything technical. It's the fast lane to divorce. Nah, Sophie, leave it to me. I'll have her writing code by the end of the year."

It had never gone that far, but Meredith had taught Lindsay more about hardware, software, hacking, and net-surfing than she'd ever needed to use. The only question it had left unanswered was what exactly Meredith did for a living that meant she had all this stuff at her fingertips. There was no secret about who she worked for - a software and electronics complex in Silicon Valley, south of San Francisco, whose income, everyone knew, came from the Pentagon. Whenever Lindsay or anyone else asked for something approximating a job description, Meredith would simply smile and shake her head. "I kill bugs. You want more details, you have to need to know, babe," she'd say. "And just being curious don't count as a need." Lindsay had sometimes wondered if even Penny had known.

Somehow, though, Meredith's silence about that crucial area of her life hadn't been a barrier between her and Lindsay. While Sophie was undoubtedly closer to Penny, Lindsay and Meredith forged a complicit bond where they played the childish role to the other pair's sensible maturity, running off to play computer games or to chase the dog along the beach when the conversation grew too serious for their mood.

But it wasn't all frivolity between them. Meredith regularly printed out obscure snippets and articles from the Internet that she thought might interest Lindsay, and often as they walked along the sand the two had debated the thorny issues around freedom of information and the preservation of personal privacy. From theoretical debate, their dialogues had moved to the personal, each sharing issues in their relationships with lovers, friends, and colleagues. While Lindsay was unequivocal in her conviction that Sophie was her closest friend, she knew too that Meredith had an important place in her life. "I have to have somebody to whine about Sophie to," she'd said once, only partly joking. She might have few complaints about her partner, but she knew herself well enough to realise that the way to keep them in perspective was to release them to someone who could point out that she was over-reacting. For Meredith, coached in a life of secrecy both professionally and personally, talking to Lindsay, no matter how sparingly or obliquely, was often her only outlet. It wasn't so surprising that she had sent Sandra Bloom after her.

Remembering what Meredith had taught her about the relentless logic of computers, Lindsay sifted through the little she knew about Penny's death. She sighed and shifted in her seat. "How did the police get on to the idea that it wasn't an accident after all?" she asked Sandra Bloom.

The detective looked up from her copy of Sense and Sensibility. "The murder method was identical to the one outlined in Ms. Varnavides' new book," she said, her tone patiently condescending.

"Yeah, I got that first time around, thanks. What I mean is, what tipped them off to the fact that Penny died the same way as her fictional victim? I'm having some trouble getting my head round the idea of some cop sitting down with Penny's laptop and scrolling through her files on the off chance of finding something that would turn an accident into a murder inquiry. It's usually the other way round, isn't it? Ignore the suspicious circumstances, call it an accident, it doesn't half cut down on the paperwork."

Sandra Bloom breathed heavily through her nose as she listened to Lindsay's irony. "According to Ms. Millers solicitor, Ms. Varnavides' agent called the police. She'd read a synopsis of the book, and she believed it was more than coincidence that her client should die in an identical way."

"Her agent? Bloody hell, that's one way to make sure you maximize your ten percent!"

"I think that's a pretty harsh judgement," Sandra said stiffly.

Lindsay snorted. "Easy seen you've not encountered many literary agents. Think about it. Penny's death is going to increase sales anyway. But murder? That's a whole different ball game. Tie your dead author in to a gruesome murder mystery that's linked in turn to her books and you've hit the jackpot. Penny Varnavides is probably going to sell more books dead than she ever did alive. But I don't suppose any of that even crossed her agent's mind when she rushed off to perform her civic duty." Her Scottish accent intensified with her sarcasm.

"It was bound to come out sooner or later," the detective said. "I expect her publishers will be doing their bit to cash in too. Somebody will presumably have to finish her final book so they can publish it. So they'd have been bound to make the connection."

"I suppose so."

"And by that stage, the waters would have been muddied by the passage of time, and it would have been that much harder to nail the killer," Sandra observed calmly.

Lindsay nodded. "You're right. In fact, you seem to be pretty good at this being right business. I don't suppose you'd want to stick around, help me out with the investigation?"

Sandra Bloom gave the first spontaneous and open smile Lindsay had seen so far. "With someone as awkward as you? No offense, Lindsay, but life's too short."

Put in her place as firmly as few had ever managed, Lindsay grunted and squirmed round in her seat, tucking her pillow under her head and pulling her blanket over her shoulders. "Wake me for breakfast. Not before," she said firmly.

You could never confuse the approaches to San Francisco and Heathrow, Lindsay thought as she stared down at the chequerboard of small fields and housing estates. Having dozed fitfully some of the way across America and the Atlantic and read the rest of the time, she'd been stupefied with lack of sleep during the transfer at Dublin Airport. At one point she'd found herself wandering dreamlike into a Doc Martens shop and trying on a pair of shiny gold boots. If it hadn't been for Sandra Bloom looming over her at the crucial moment, she might even have bought them. But now she was grittily awake, feeling faintly sick, and aware that the long flight had just been a way of putting things on hold. In a few minutes, they would land, and she'd be in the thick of things. Penny's death, Meredith's grief, and someone's guilt would have to be dealt with. She wished she'd waited for Sophie.

Baggage reclaim, customs, and immigration were swift and painless. The two women emerged into the main concourse, Lindsay apprehensive, Sandra relieved. Straight ahead, Meredith bent one arm at the elbow in a halfhearted wave. The forlorn gesture knocked Lindsay on her heels with its pathos. Then she surged forward, leaving Sandra to take charge of the abandoned luggage trolley, and swept Meredith into her arms.

For a long minute, the two women rocked each other back and forth wordlessly. For Lindsay, who knew the pain of losing a lover to death, it was as if Meredith's agony was seeping into her by osmosis, taking her back to a place she thought she'd left far behind. All Meredith was aware of was the comfort of a familiar face, a familiar shape in her grasp.

It was Meredith who pulled back first. "You'll never know how much this means," she said, her voice cracking.

"Couldn't just abandon you," Lindsay said. As soon as the words were spoken, she knew they were the truth. There had never really been any chance of Sandra Bloom coming back empty-handed. "I'm so sorry," she added.

Meredith nodded, biting her lip, clearly battling tears. Lindsay put her arm around her, and they moved away from the incoming passengers and their meeters and greeters. Out of the corner of her eye, she was aware of Sandra Bloom conferring with a woman in a dark trouser suit, a mac thrown with stylish lack of care over her shoulders. Where Lindsay and Meredith moved, they followed.

Lindsay steered Meredith into a chair in a quiet corner away from the crowds. "Okay?" she asked anxiously, watching Meredith blow her already red nose and dab at puffy eyes with a crumpled tissue.

The woman in the suit stepped forward. "I'm Geri Cusack," she said, the soft blur of an Irish accent still evident enough almost to swallow the vowel on the end of her first name. "Meredith's solicitor."

More sexily slurred vowels, Lindsay couldn't help noticing. She'd also taken in the straight shoulders and the gentler curves below, the reddish hair and hazel eyes set in a face shaped like a pre-raphaelite maiden. The features, though, were far too strong to appeal to any painter whose idea of womanhood fell on the submissive side of the fence. Geri Cusack, Lindsay decided, was not a woman to mess with. Wherever Meredith had found her, it hadn't been first pick in the Yellow Pages. "It was good of you to bring Meredith to meet me," she said. "We'll manage now."

"I don't think you appreciate the gravity..." Sandra Bloom started. Geri Cusack raised her hand in a warning gesture, and the detective's words trailed off.

"Sandra, would you wait with Meredith a minute? Me and Ms. Gordon need to have a word."

Lindsay, half in love with the lawyer's voice, followed her meekly for a few yards. "I meant it," she said. "We'll manage now."

"That's fine. I understand you need to ask her things it would be as well I didn't know the answers to. That's the way it goes in difficult cases like these. I don't have a problem with it. I just wanted to fill you in on where we're up to. Saturday evening, she was arrested and taken in for questioning. They were concentrating on establishing that she knew about the murder method in the book, and on where she was at the time they think Penny was killed. She doesn't have anything approaching an alibi. But they've got nothing on her except the thinnest of circumstantial evidence so they've released her on police bail."

"They wouldn't want the custody time to run out without enough evidence to charge her," Lindsay said sourly.

"You know how the Police and Criminal Evidence Act works? That might come in handy. Anyway, she's been advised not to attempt to leave the country and to report back to the police station on Friday morning. Just so's you know."

"And you want what, exactly?"

Her wide mouth twitched in what looked like a half smile, half grimace. "My client's instructions were to get you here so you could establish her innocence. I think I'd settle for that."

"Nothing too difficult, then," Lindsay muttered.

"Not for you, according to Meredith." Her eyebrows rose momentarily. If it hadn't been a wildly inappropriate moment, Lindsay would have been convinced she was flirting. As it was, she decided, it was simply part of a formidable armoury Geri Cusack dedicated to the greater good of her clients. "I'll let you get on," the lawyer said.

Lindsay stayed where she was for a moment, watching Geri Cusack say farewell to her client and scoop Sandra Bloom up in her wake. Then she moved across to Meredith and sat down beside her, taking her hand and squeezing it gently. Meredith stared bleakly at Lindsay with the red-rimmed eyes of a sick and bewildered child. "I didn't kill her," she said. "God knows, I felt like it, but I didn't do it."