Lindsay pointed to the screen. "Look there," she said, indicating with the cursor what she wanted Sophie to pay attention to. "It wasn't the manuscript of Heart of Glass that the killer was after. It was the notes for the next one. Structure: five sections, alternate POV between Sam McQueen and Martha Denny: The Invisible Man, The High Cost of Living, The Ghost Road, The Information, Crime and Punishment," she read out. "One of the few pieces of paper left in the flat had those titles written on it. I thought it was a reading list when I first saw it, but she was obviously starting to think about a new novel. She was going to call each of the sections after a book."

Sophie nodded. "Yeah, so far so clear. But what's that got to do with Penny's death?"

Lindsay scrolled down further. "Outline," Sophie read over her shoulder. "Chicago??? NYC??? Sam McQueen: early thirties, Irish/Italian, third-generation respectable face of the Mob, has legitimate front business - ??? magazine publishing??? Hits on a way of cleaning up the lives of serious criminals. He turns his publishing house into a money laundry. Step one - makes Mob figures respectable; hires them as commissioning editors on huge salary. Every month, the company pays their salaries into offshore accounts, then the money comes back into their U.S.-based accounts from the offshore bank. But what really happens is Sam's firm pays the money into an account in Sam's name offshore. And the 'employees' bring in their own dirty money from offshore into their domestic bank account, thus making dirty money look clean. Not only that, but they are legitimized in the eyes of the government - they pay taxes, they have Social Security numbers, they pay insurance, and they earn hugely inflated salaries because they are shit-hot editors - ho, ho, ho!"

"My God," Sophie breathed. "That's bloody clever."

"You're not kidding. It gets better, though," Lindsay said drily, flicking the "page down" key to bring up a fresh screen.

"In order to pay these non-productive, fake employees, the company has to have a much higher turnover. They pretend to produce fake magazines, which are sent to outlets that are Mob fronts. Outlet claims to have sold, say, 100 copies of computer magazines per week, thus legitimately putting an extra $500 through their till. They pay Sam's company for the magazine at wholesale, say $250 a week. And so Sam has, on paper, a string of highly profitable magazines with a team of commissioning editors. Only nothing is real."

Sophie looked up and grinned admiringly. "That is wicked," she said. "That is so clever. Where on earth did Penny get an idea like that? I never heard her show any interest in that kind of scam, did you? She was always much more interested in the psychology and sociology of lawbreaking than the mechanics."

"Read on," Lindsay said, gesturing toward the screen. Sophie scrolled down and carried on reading. "Sam's a keen yachtsman, likes racing yachts. One weekend, he's sailing, and he meets a woman who's crewing on the yacht he's helming. Martha Denny. Twenty-nine, undercover Treasury agent working on anti-racketeering crackdown. She's infiltrated Sam's social world to try and gather information on Mob-related activities. He thinks she's a photographer, and he falls for her. Soon, they're lovers - Martha battles with conscience as government agent, but figures he's clean, his company is clearly legit. Then odd things start happening. He gets his magazines to commission her to take pics, so she's around the office a lot. She notices a lot of calls come in for people who are never there; messages get taken, and presumably passed on, but she never meets the guys attached to those names. Then she finds out they all supposedly work on the mysterious tenth floor - in a nine-story building???

"Martha's torn between love and duty. (Watch out - bit of a clich¨¦? Or is that just men?) Sam realising early on that she's got suspicions, but he loves her too much to want to lose her so at first he finds justifications and then has to cope with idea of?? Martha dead ?? or ?? himself dead ?? if his Mob connections find out he's harboring a viper in their midst.

"Resolution???"

Sophie took a deep breath and exhaled slowly. "Powerful stuff," she said. "I mean, it's a great story by any standards, but when you know what Penny could have done with it... it makes her death seem so much more tragic. I know that's a terrible thing to say, like saying some people's deaths are more significant than others, but that's how I feel about Penny." She buried her face in her hands, feeling the prickle of tears in her eyes.

Lindsay pushed the laptop to one side and put her arm round her partner's shoulders, hugging her as close as her painful body would allow. "You're right to feel like that. Penny was special. Most of us, if we make a difference to the lives of the people we care about, we're doing well. But Penny made a difference in a lot of people's lives, thousands of them strangers. She'll go on doing that for a lot of people, but all the books she still had to write won't get written now, and we're all poorer for it."

Sophie leaned against Lindsay and smiled sadly. "I'm really going to miss her. You know how it is with couples you spend a lot of time with - you tend to pair off crosswise as well. I always felt you were closer to Meredith than I was, and I was closer to Penny. I talked about things with Penny that I didn't discuss with many people."

Lindsay sighed. "You're right. I loved Penny, but she could do my head in sometimes. When she got into her New Age meaning of life stuff, it was time for me to go and hug a PC. Or sneak off to Burger King with Meredith." They sat together in companionable silence for a moment, each busy with their own memories.

Then Sophie remembered what she'd come upstairs for. "You said this was it, the message that explained why Penny had to die. I don't understand. Are you saying it was a Mafia hit?"

"There's more than one kind of organised crime," she said. "Look at all the clues in the texts. Who published Penny's novels? Monarch Press, owned by Danny King. Doesn't that sound a lot like Sam McQueen?"

"That's a bit thin," Sophie protested.

"Is it? Let's not forget that Danny King is one generation away from the old-fashioned East End, where organised crime flourished. It didn't die just because they put the Krays behind bars. It's still going on. The gangland families are just as powerful as they ever were. More so, probably. They've spread out into Essex and branched out into drugs, but they're still basically the same mobs who have run London since Jack the Ripper was pulling the wings off flies. Just say, for the sake of argument, that Danny didn't use his pools winnings to set up Monarch - what if he used dirty money from friends of the family to get the business up and running and turning a legitimate profit?"

Sophie looked skeptical. "Isn't this all a bit far-fetched, Lindsay? We're talking a London publishing house, not a New York casino."

"You think publishers can't be crooks, too?"

"Not like this, no. It sounds like a bad gangster movie script."

"This isn't a gangster movie, it's a hi-tech thriller," Lindsay replied, her voice bitter and sharp. "One of those ones where somebody gets burned because they pick up too many pieces of the jigsaw by accident, and suddenly they're looking at the whole picture. That's what happened to Penny."

"But how? Penny wasn't an undercover FBI agent. She was just an ordinary writer."

"She was an observer," Lindsay pointed out. "Penny was shrewd and sharp when it came to watching people. That's why her psychology was always so spot on, why her characters felt so real. Think about it. All those afternoons she spent at the mall or the bowling alley, hanging out, watching the teenagers, listening to them, absorbing everything about their culture. And she had that uncanny skill for identifying what was a nine-day wonder and what was a genuine trend that would still have resonance for her readers five or ten years down the road. You mean to tell me that if the jigsaw pieces were there for the grabbing, Penny wouldn't have gone for them with both hands?"

Sophie disentangled herself from Lindsay's encircling arm and got up, fanning herself with her hand. "Nothing personal, I was just overheating. I can't believe this weather, it's hotter than at home." She sat down by the open window, trying to convince herself there was a breeze. "So what were these jigsaw pieces you reckon Penny picked up on?"

"The phone messages. When I read that in her synopsis, I knew exactly what she meant. I didn't really register it at the time, but both times I've been at Monarch, Lauren the receptionist has dealt with phone calls a bit strangely. Some are totally routine - 'Hold the line, I'll see if she's free,' 'Hold the line, I'll put you through to her secretary,' that sort of thing. But there were others where she said straight off, 'I'm sorry, he's not here, can I take a message?' Not, 'Let me see if he's available.' Or, 'He'll be in later, can I get him to call you?' Or, 'Would you like to speak to his secretary?' Just a flat offer to take a message. But if Danny King's operating a ghost-employee scam, that would be exactly what would happen!" Lindsay's voice was excited, her eyes sparkling for the first time since Sophie had arrived in the UK.

Sophie frowned. "Okay, I grant you it makes a certain kind of sense if you reason it backward. But how did Penny get from noticing a peculiarity in the receptionist's phone habits to working out the whole ghost-employee scam? I mean, you heard the same thing, and it meant nothing suspicious to you until you understood what was really going on."

Lindsay shrugged, then glanced at the bedside clock. "I don't know the answer to that. But I know a woman who might. And with a bit of luck, I might just catch her."

Sophie looked around the caf¨¦ with a critical eye. "A bit gloomy, isn't it? You'd think she'd be glad of the chance to get a bit of sunshine on her day off." Judging by the absence of other lunchtime patrons, everyone else was doing just that.

Lindsay shook her head. "She doesn't want to risk being seen with me. Even on a Saturday. Lauren has the same relationship to Monarch as a flea has to a cat, which means she doesn't want to risk losing her meal ticket, though she's not averse to a nibble elsewhere as long as the price is right."

"One look at you, and she might think twice about opening her mouth," Sophie commented, gesturing at her own cheek to illustrate her point.

Another night had spread Lindsay's bruises up and across her face to engulf her eye as well as her cheek and jaw. Time had rendered them more lurid shades of blue, with green and yellow making an appearance round the edges. The scabs covering her grazes had darkened, looking like mud that had been flicked over her skin and allowed to dry there. Under Sophie's gentle bathing, the dried blood had been cleaned from the long hairline cut along her jaw, leaving it looking far less serious than it had done the day before. The pain had subsided to a gentle throb, the ache dulled by the paracetamol Lindsay was still swallowing at four-hourly intervals. "I'll just have to tell her the truth," she said wryly.

"Let's hope she shows up," Sophie said.

"Yeah. Before the cops decide they've got enough circumstantial evidence to charge Meredith," Lindsay said glumly. "They're not going to wait forever, and they obviously think they know who did it. Which means nobody except us is looking for the real killer. Who thinks he's got away with it." As she spoke, she saw Lauren walk in, and waved at the receptionist. "Over here," she called.

Lauren walked toward them. When she saw Lindsay's face, her double-take was almost comical. Her face fell like a failed souffl¨¦, and her step faltered. Cautiously, she approached. "What the fuck happened to you?" she said wonderingly. "You look like you just went ten rounds with Freddy Kruger. I don't think I wanna be here." She took a step backward.

"I had an accident," Lindsay said hastily. "It's the truth. I took a header over a wall I didn't know was there and landed on top of a broken bottle. Nobody's had a go at me."

"She's telling the truth," Sophie butted in. "I'm a doctor and believe me, her injuries are consistent with that explanation. Look at those grazes - you don't get skin damage like that in a straightforward beating."

Lauren scowled. "Who the hell are you anyway?" she demanded of Sophie, then rounded on Lindsay. "I'm taking a risk, coming here to talk to you. What d'you want to bring a stranger along with you for?"

Lindsay sighed. "Sophie is my girlfriend. She also happens to be a doctor, and on both counts she wasn't about to let me out of the door by myself this morning. It's okay, Lauren, you can trust her. Sophie was Penny's best friend back in California."

Lauren looked uncertainly from one to the other. Something in Sophie's steady eyes calmed her, and she sat down abruptly. "You going to get me something to drink, then?"

"I'll go," Sophie said, taking details of what everyone wanted.

While she collected drinks and food, Lauren said, "You better be making this worth my while. Baz was having a right go about you yesterday, talking the piss something shocking. About how you was accusing her of murder, then Danny walks in, and points out that she was doing a live radio show when it happened. And Baz says to me that if you turn up again looking for her, I'm to show you the door. So this better be good."

Lindsay nodded calmly. "I hear what you're saying. You'll be well looked after, I promise you. First off, I've got a couple of questions, but if you don't mind, I'd rather wait till Sophie comes back."

Lauren's eyebrows flicked upwards in bored exasperation. Her response was to take out her cigarettes and light up. "What do you need her for?" she asked petulantly.

"Because my brain's still cabbaged from all the painkillers the hospital shoved into me when I did my swallow dive on to the asphalt. Chances are I won't remember all the things I need to know. Okay?" Lindsay said mildly.

"I suppose." Lauren smoked furiously, her lips pursed between inhalations. When Sophie rejoined them with mineral water and sandwiches, she ostentatiously crushed out her cigarette. "So how much are you offering me?" she demanded, all empty belligerence.

"How does two and a half sound?" Lindsay said. "That's a final offer, by the way. Non-negotiable."

"Two hundred and fifty?" Lauren squeaked, impressed in spite of herself. Then suspicion kicked in. "What d'you want me to do that's worth that kind of money? I ain't putting myself at risk here."

"Pretty much the same as you did for Penny. Let us in the building today, and we'll drop the keys off with you later." '

"There'll be people there. Working."

"On a Saturday?" Lindsay sounded incredulous.

"You've got no idea. Workaholics, some of them. Brown noses, the rest of them. Think just because Danny sometimes drops in on a Saturday that they'll get Brownie points if he sees them at their desk. Saddos."

"So what time do they leave?" Sophie asked.

"Look, what are you going to do in there? I'm not going along with anything criminal, like trashing the place." Lauren's voice was apprehensive underneath a superficial bravado.

"Nobody will even know we've been in there," Lindsay promised. "All I want to do is exactly what Penny did. There's something I need to check out for myself, just like she did."

Lauren picked up one of the sandwiches and tore into it as if she hadn't seen food for a week. "How do I know you're telling me the truth?" she said through a mouthful of sandwich.

Lindsay shrugged as Sophie leaned forward, pinning Lauren with her eyes. "You have to trust us, Lauren. Lindsay told me how fond you were of Penny. Well, so was I. She was my best friend. I know we're asking you to take a big risk, but we're not asking for fun. This is as serious as it ever gets, Lauren. This is about my best friend's death, and I am absolutely determined to find out what really happened to her. Now, if you want to help, I'd be delighted to accept your assistance. But if it's too much to ask, that's okay, too. We'll just have to find another way of getting at what we need."

Lauren gave up trying to outstare Sophie and mumbled, "All right. But this is the last time I take any chances, okay?"

Sophie reached out and touched Lauren's shoulder. "Thanks."

"Cash, mind," Lauren said gruffly. "Up front."

Lindsay took out an envelope and pushed it across the table. Lauren paused for a moment, her eyes going from one to the other in a flinching gaze. Then she snatched up the envelope and ripped it open, revealing five new fifty-pound notes. Glancing quickly round her to make sure no one was watching, she held them up to the light to check metal strip and watermark. "Oh, yeah," Lindsay said with a tinge of sarcasm, "I really look like a big-time forger."

Lauren gave a sunny grin. "All I know, you could be Al Capone. Right now, I couldn't care less. Be outside the office at half past five. They'll all have gone by then. I'll let you in." She grabbed her bag and stuffed the envelope in an inside zipped pocket. Then, picking up the remains of her sandwich she pushed back from the table, about to leave.

"Wait a minute," Lindsay said. "One or two questions, remember?"

Again the "Oh, God" upward flick of the eyebrows, accompanied by the heavy sigh of the hard done by. "All right, then, what do you want to know?"

"The couple of times I've been in reception, I've noticed you taking messages for people without checking if they were in. Is that a regular thing?"

Lauren frowned. "Yeah. I've got a list of about a dozen blokes. They never come in the office, but I get messages for them regular."

"What do you do with the messages?" Lindsay asked. The hair on the back of her neck seemed to be standing on end and, in spite of the stuffy heat inside the caf¨¦, she felt a chill inside. So much hung on Lauren's answer.

"I pass them on to Danny's secretary. When I started working on reception, I asked who they all were, and she said they were business associates of Danny's. She said they were consultants who didn't have offices with secretaries of their own, and it was convenient for them to be able to leave messages here. I thought they must be a right bunch of tossers if they couldn't spring for a mobile phone or voicemail or something."

Lindsay let out the breath she hadn't been aware of holding. "Thanks, Lauren," she said softly. "We'll see you tonight."

She nodded and gathered up her bag, pausing to light a cigarette. "Funny you should ask about the messages," she said conversationally. "Penny wondered the very same thing."