Thunderstruck, Lindsay's head swung from Danny to Baz and back to Danny again like a nodding dog on a car parcel shelf. "Alibi?" she said faintly, clinging to the hope that life would imitate crime fiction, where alibis, like rules, were made to be broken.

"Obviously not," Danny chuckled. "Go on, Baz, put her out of her misery."

Baz's tight-lipped smile was closer to a sneer. "I was taking part in a panel of agents and publishers at a literary festival in Colchester at the time Penny died," she said smugly. "I travelled down by car with Elizabeth Root. She's an agent, her office is a few minutes' walk from here. We had a drink together, then did the panel - which, incidentally, was broadcast live by Oyster FM. All four of us on the panel went for a meal afterwards, and I didn't get back to London until nearly midnight. As I explained to the police the following day," she added with a vicious little smirk.

Danny moved into the office and laid a friendly arm across Lindsay's shoulder. "So you see, I'm afraid you're barking up the wrong tree with Baz. Whoever killed Penny, it was nothing to do with Monarch Press."

Lindsay edged away from Danny's arm, making the excuse of standing up and moving toward the door. "Just because Baz seems to be off the hook, it doesn't mean Monarch is in the clear," she said in an attempt at a defiant face-saver.

Danny opened his mouth but before he could say anything, Baz butted in. "She's got the book," she said urgently.

He looked astonished. "You managed to track it down?" he said. "But that's... that's amazing. Wonderful. How soon can you let us have it?"

"It's not up to me to let you have anything," Lindsay said stubbornly. "It's up to Meredith. She inherits everything from Penny. She might not want you to have it."

"She's got to, I'm afraid," Danny King said, his patronizing tone setting Lindsay's hackles on full-scale bullshit alert. "Penny signed a contract. She'd been paid the first chunk of a very substantial advance. The biggest we've ever paid, as a matter of fact. That manuscript belongs to us."

Lindsay shook her head. "Not if Meredith decides to repay the advance," she pointed out as she sailed out of the office, head held high.

The satisfaction of her parting shot lasted for as long as it took her to cross the rapt editorial floor and reach the street. Never had she been more grateful to breathe the fumid air of a steamy London morning. Without hesitating or allowing herself to think about what she'd just experienced, Lindsay strode across the supermarket car park and into their blissfully air-conditioned cafeteria, where she found a quiet corner to drink her mineral water and regroup.

She had been so certain that Baz had killed Penny. Ever since Sophie had passed on the information about the changes to the latest draft, she'd been running the film in her head of Penny inviting Baz to her flat, maybe even for a showdown over Meredith; of Baz arriving with her bottles of wheat beer, then of the murderous attack that had left Penny bleeding to death somewhere as prosaic as an Islington kitchen.

But she'd been wrong. Completely, utterly wrong. Her first serious suspect, Catriona Poison, had been stripped of motive. Now Baz Burton had been revealed as devoid of opportunity. Of the limited group of suspects she'd started with, only Meredith remained. And since she'd known from the start that while Meredith might have killed Penny in a moment of passion, so carefully staged a crime was beyond her, Lindsay was left with no one in the frame.

There was nothing for her to do now except admit to Meredith that she was utterly defeated by the mystery of Penny's death. With a sigh that turned heads at nearby tables, Lindsay acknowledged to herself that she had failed not only Meredith but also Penny. Although her mind knew it for an overreaction, her heart comprehended it as a betrayal of a friendship that had often sustained Lindsay when she needed it most. To admit that failure to Meredith of all people would be one of the hardest things she had ever faced. Leaving most of her drink untouched, Lindsay walked out into the sunshine and headed for the tube station.

She caught Meredith coming back from buying the newspapers. "At least they've lost interest in me right now. Kinda late, though," Meredith had said as they went up in the lift. She had visibly lost weight even in the short time since Lindsay had last seen her. Her eyes lurked at the bottom of darkly shadowed sockets, and her cheekbones seemed on the point of bursting through her taut skin.

"When did you eat last?" Lindsay had asked while she watched Meredith make them coffee.

"I went out for a pizza last night," Meredith said. "I managed to get some down. But it's hard to eat. I feel like I've got a rock lodged in my throat." Lindsay's heart went out to her, and she reached out impulsively to hug her friend. But this time, Meredith's grief didn't burst forth like an undammed stream. She sighed deeply, but her hand mirrored Lindsay's, each stroking the other's back in mutual sympathy. "When you love somebody and you commit yourself to sharing her life, you can't help imagining what it would be like if she died," she said softly. "Only nothing you imagine ever prepares you for the reality."

"I know," was all Lindsay could manage. They held on to each other until the urgent spluttering of the coffee pot forced them apart. Then, sitting with Meredith in the stuffy gloom of the flat, Lindsay reviewed what she had done in the previous couple of days. "I've hit a dead end," Lindsay confessed finally. "I really don't have any idea what to pursue."

Meredith nodded sadly. "I guess it was a long shot, bringing you over here. But don't think I don't appreciate it. There is one other thing you could do for me, though," she added, almost as an afterthought.

"Sure, if I can."

"Leave me a copy of Heart of Glass. I think it would be good for me to see the last thing she was working on. I also need to decide if it's possible for another person to finish what she'd started."

Lindsay rooted in her backpack and came up with the floppy disks on which she'd made back-up copies of the files Sophie had e-mailed to her. "There you go," she said, passing them across.

"I've not got the final draft yet, but I should have it some time this evening. Are you on-line here?"

Meredith gestured with her thumb toward a repro Regency table where a laptop sat incongruously. "Sure. Did you want to e-mail it to me? You've got my address, yeah?"

"Soon as I've got it, I'll shunt it on to you."

"Who knows?" Meredith said wistfully. "There might be something there that'll give us a clue. Maybe even point you in a fresh direction."

Lindsay shrugged. "I wouldn't hold out too much hope. But if there is anything there, you can rest assured I'll be on to it like a rat up a drain." She finished her coffee and got to her feet. "I've got to go now, Meredith. I've got a bit of business to sort out for Helen. But I'll be in touch."

Out in the sunshine again, Lindsay sought out the shade of the plane trees that lined the street. She could escape the merciless heat, but there was no escaping the overwhelming guilt she felt at her failure to exonerate Meredith. She'd blown any attempt to place the blame for Penny's death at someone else's door; she hadn't even managed to come up with any concrete evidence that would clear her friend. And her ridiculous antics with Derek Knight meant she didn't dare to return to Islington to question the neighbours on the off chance that someone had seen something that would cast doubt on the police's seeming conviction that in Meredith they had found the killer.

No matter how she cut it, she couldn't see any way forward. To someone as stubborn as Lindsay, it was a bitter blow. But she was no quitter. If she couldn't go forward, maybe she could go backward. As soon as Sophie managed to snatch a moment to send her Penny's final draft, Lindsay decided, it was time to start working in a completely different direction.

Just after seven, Lindsay faced Helen across Stella's desk, the terminal in front of her switched on, with Lindsay logged in as a super-user. "Okay," she said. "This is how it goes. Companies like Watergaw need to pay kickbacks and bribes if they're going to operate in certain countries. Traditionally, the Inland Revenue have taken the view that, while payments like these aren't strictly tax-deductible, if they go through the balance sheet as commissions paid to third parties, they'll turn a blind eye and allow the company to offset them against their profits. However, a couple of years ago they announced they weren't going to allow that any more. In practice, nothing has changed, it's just that the Revenue have taken a position that means they keep their hands clean. And every now and again, they'll do somebody, just to keep everybody else on their toes."

"Yeah, yeah, I know all that," Helen said impatiently. "I still don't see how you're going to use it to nail Guy and Stella. We're a minnow compared to the multinationals that get away with it every day of the week."

"Bear with me," Lindsay said. "This is where it starts to get interesting. There are two separate issues that make it possible to create a scenario that looks very unpleasant for Guy and Stella. First, you have to consider why the tax authorities have been prepared to look the other way. Why do you think that might be?"

Helen shrugged. "Because the companies involved go out there to make a tasty profit? And if the taxman stopped them paying bribes, their nice healthy profits wouldn't be there to be taxed in the first place?"

"More or less. Traditionally, it's been the manufacturing and service sectors that have benefited from this selective blindness. That's because the Revenue are perfectly well aware that if our companies don't win contracts, they go to our competitors in Europe and America and, increasingly, on the Pacific rim. So not only do we lose taxable profits, we ultimately lose more jobs. Which is not something this government can afford."

Helen nodded, on familiar ground. "Even if it means turning us into the Taiwan of Europe, outside the Social Chapter, and without a single employment right among us."

"So in those terms, technically what you've been doing at Watergaw falls into a grey area. It's not the kind of fraud that gets the taxman too excited. It's not like some companies, where they set up a dummy outfit in a tax haven and pay the commissions through that," Lindsay added.

"What's wrong with that?"

"In itself, nothing. But in practice, what usually happens is that for every ten dollars that goes out in bribes, a couple go into a separate numbered bank account for the company's directors. So they can pay themselves a tasty tax-free bonus for being clever enough to bribe their clients."

Helen shook her head. "You know, the sheer deviousness of financial crooks never ceases to amaze me. But this still doesn't explain how you're going to drop Guy and Stella in it."

Lindsay sighed. It wasn't as if she really understood all the ins and outs herself, only the bare bones on which Ellie had put sufficient flesh for her to understand what she had to do. Explaining it to Helen was turning out to be more difficult than she had anticipated. Still, it was good experience for getting it straight in her own mind before she tried to put the theory into practice. "Watergaw isn't a manufacturer, in the sense of making something for export. It's not a service company in the sense of earning money for Britain by selling insurance or financial services abroad. The bribes you've paid have been handed over to make your filming run smoothly, yeah?"

"Of course. You'd never believe some of the things you have to hand out the readies for. I've paid people to muzzle their goats so they wouldn't bleat at a crucial moment. I've paid yobs to let actors walk down their street without them mooning in the back-ground. I've paid traffic cops not to give parking tickets to film units. I once bought fried-chicken dinners for an entire African village and laid on the coaches to take them to and from the fast-food stall." Helen leaned back in her chair with the air of a woman who has only just opened the doors on her stock of anecdotes.

"Exactly," Lindsay said hastily. "And what would happen if you hadn't paid those bribes?

Helen frowned. "We wouldn't have got the films made."

"And would people have lost their jobs if you hadn't been able to make those films?"

"Well, probably if we'd gone out there and then not been in a position to film."

"But if you'd known in advance that you'd be penalized for paying kickbacks, you'd have been crazier to contemplate making those films, right?"

Helen frowned, unable to see where Lindsay was heading. "Right. So we'd have made other films instead. Films set over here. Or in developed countries where the bribe culture is more or less dead."

"My point exactly," Lindsay said triumphantly. "For manufacturers, the paying of bribes is a necessary business expense or else they go to the wall. For you, it's a luxury. You could conceivably make other films that would equally ensure your continued success. So if someone grassed you up to the taxman, you'd be a perfect case to use to trumpet to the world that this government is encouraging the Inland Revenue to clamp down on corruption."

Helen looked gobsmacked. "You are fucking wicked," she said admiringly.

"You've only heard the half of it. Customs and Excise have never really gone along with the Revenue on this one. Their view has always been that if there's anything in the VAT accounts that looks dodgy, they'll come down like a ton of bricks. Mostly, foreign kickbacks don't have any impact on the amount of VAT a company's due to pay. But there are circumstances where they do - like if you've disguised a bribe as a payment for goods or services and you've paid it to a company with a UK subsidiary. Would there be anything like that in these accounts?"

"Oh, yeah," Helen said eagerly. "I can show you, if you like." She pulled the monitor toward her so she could see the screen. Lindsay passed the keyboard across, and Helen moved expertly through a set of accounts till she found what she was looking for. "We keep the accounts for each project totally separate," she said as she moved the cursor down a list of payments. "This is Thirty/Three, Guy and Stella's little honeymoon on the subcontinent. There, that's what I'm looking for. Canopus Islamabad." She double-clicked on the file. A window popped open detailing dates and amounts of payments. "We hire our lighting from them. We pay them in the UK, with a hefty slice on top of the actual hiring charge."

"Perfect," Lindsay said softly. "Now I need you to show me the way round your accounts software."

"You're not going to alter them, are you?" Helen asked, looking aghast.

"Nothing that crude," Lindsay said. "I just want to get familiar with the ins and outs of what was paid, when it was paid, and who got the cash. Then I can get to work."

"So what are you going to do?" Helen nagged.

"I'm going to plant some files in Stella's personal desk. And some in Guy's. I can't tell you the details, because I don't know what they are yet."

"Are you sure you know what you're doing?" Helen asked, worry replacing fury for the first time since Lindsay had revealed Stella and Guy's racket to her.

"Sort of. Where I don't, I know a woman who does. And she's only a phone call away. Helen, you've got to trust me on this. Unless you've got any better ideas, I'm your best chance of getting that pair out of your life for good."

Helen fiddled with a strand of hair, a strangely coy gesture from a woman normally so upfront she made Roseanne look demure. "I just don't want you getting in too deep," she said.

"I think I can look after myself," Lindsay said gruffly. "Now, are you going to show me how this bloody software works, or do I have to work it out for myself?"

An hour later, Helen reluctantly left. She had given Lindsay a swift tutorial in both the accounts and the word processing packages that Watergaw used as standard on their network of computers. Then Lindsay had insisted she go home. "It's better you don't see how I do this," she said. "That way you can't let anything slip."

Left to her own devices, Lindsay spent a couple of hours gaining a thorough grasp of the payments that had been made as part of the production budget of Thirty/Three, taking notes as she went. Then, exploiting her super-user status, she changed the computer's internal date stamp so that it read a few days after Stella had joined the company. Next she entered Guy's private directory and created a memo, dated to correspond with the new internal date on the computer. The long document outlined for Stella's benefit a series of fraudulent practices which "Guy" explained were standard. It also contained a caveat warning Stella not to discuss these procedures with Helen. "Our partner," Lindsay typed, "has rather old-fashioned views on fiscal matters. I have tried in the past to explain to her how the real world works, but her response hasn't encouraged me. However, she doesn't have enough experience of commercial matters to unravel the accounts I prepare for her. When we set up the company, I promised her faithfully I would be fiscally prudent, and she took that to mean I'd stick to the letter of the law. You've no idea how liberating it is to be working with someone like you, who understands the realities. It's a jungle out there, and we need to use whatever weapons come to hand so we can survive. Besides, everybody rips off the taxman and the VATman. It's the national sport."

Then, changing the internal date to the following day, she moved to Stella's personal desk and produced a second memo, acknowledging Guy's to her and suggesting a couple of dodgy wrinkles of her own. Next, she changed the computer's date to that of a couple of weeks after the end of filming on Thirty/Three. With constant reference to her notes, she constructed a long memo purporting to come from Stella to Guy, explaining in detail the subterfuges she had employed to disguise the crooked payments. It finished with a contemptuous reference to Helen, looking forward to a time when she and Guy could dump her from the partnership. Finally, after changing the internal date on the computer to the correct one, she printed out all three memos.

It took a little longer to make them look appropriately aged. A coffee mug ring here, a smudge of cigarette ash there. Here a curl at the corner, there a crease. Her piece de resistance, Lindsay felt, was to copy a doodle she saw replicated a dozen times on Stella's scratch pad, a five-pointed star with the central pentagon inked in. Then she put Guy's into Stella's desk drawer, toward the bottom of the pile of papers in there. She walked down the dim corridor to Guy's office, where she deposited the fake memos from Stella among a stack of papers in a deep tray marked "To be filed when hell freezes over."

Back at the computer, she used the system's in-built retrieval system to recapture the forged EU letter about Helen's grant which Stella had deleted the previous evening in her and Guy's attempts to cover their tracks. Like most people, she had once thought deleting something was enough to erase it from the system forever. Thanks to Meredith's teaching, Lindsay now knew different.

Finally, she made a lengthy call. Just after midnight, Lindsay put the phone down. She had run the final details past Ellie and been assured that what she had put in place was the perfect frame that would cheerfully convince any investigator from Customs and Excise or the Inland Revenue. One of the knock-on effects of new technology that usually worried her was how easy it had become to frame the innocent. It made a pleasant change to exploit it against the guilty. She stretched her back, thrusting her arms into the air, and yawning like a basking lioness. The sooner she got back to a routine where she could run and work out, the better she'd feel.

She switched off the computer and gathered her papers together, making sure she had left only the materials she wanted the investigators to unearth all by themselves. Then she let herself out of Stella's office and headed for the exit. There, she consulted the note Helen had given her and set the alarm as she opened the door to the car park. As Watergaw's door closed behind her with a sharp click, Lindsay was uneasily aware of how dark the car park was. She could have sworn she'd previously noticed security lights mounted on the side of the building, angled to shine across the car park, but now the only light came from the distant streetlights, reduced even further by the bulk of the Watergaw building.

Swallowing her apprehension, Lindsay walked boldly along the side of the building to the street where she could hail a cab. Suddenly, she was aware of glass crunching under her feet and she stooped to look more closely. As she registered the broken glass of the security lights, she heard the soft footfall of running trainers on asphalt. Startled, Lindsay jumped up and swung round to face the direction of the sound. As she turned, she saw outlined against the pale orange of the sodium streetlights the unmistakable shape of a baseball bat. It was heading straight toward her as if she was the pitcher's finest curve ball.