She shrugged. 'If I can remember, certainly. But this was a while ago and, as I said, there was nobody special.'

'But Richard Greville was?'

'Certainly more special than anyone else before.'

He nodded, although he felt far from satisfied. He couldn't force her to talk but he was determined to find out one way or another. He decided to try a different tack. 'How would you describe her? I gather she didn't find relationships easy?'

She seemed to consider the question then shook her head. 'No. She was shy and shyness makes people awkward, cuts them off. Rachel just found it difficult to form emotional ties. It's a defence mechanism. I think, beneath it all, she was frightened of exposing herself, of getting hurt.'

'It's early days but it's likely she was killed by a man and probably someone she knew,' he said forcefully, catching her eye. 'Come on, you were her best friend. You really expect me to believe she told you nothing about what was going on in her life?'

She flushed. The knuckles of her hands were white as she clenched her fingers in her lap. 'Perhaps there was nothing to tell.'

Running his fingers through his hair, he leaned forward towards her, trying to bridge the gap between them. 'Nothing to tell? Look: maybe you're trying to protect your friend out of some sort of misguided loyalty, but she must have had a life outside work and, if you were as close as you say you were, you must have known about it. Even if they don't live in each other's pockets, women talk. They can't help confiding in their friends. Whether you were in the US or London, there's the phone and the email. We'll be checking the records to see what was really going on.'

Tight-lipped, Liz held his gaze, but she didn't reply. He could see the pain and stubborn defensiveness in her eyes, and there was no point in going any further for the moment. He had to let her calm down first. Maybe then she would be more prepared to open up.

He stood up and Feeney followed suit. 'Thank you. I'll be in touch if there's anything else. One last question. For formality's sake, could you tell us what your movements were last Friday morning?'

She looked startled, as if she wasn't expecting the question. 'I was here. In this flat. Surely you don't think I-'

'It's just a formality. Please answer the question.'

'I flew in from New York first thing on Thursday.'

'So, Friday morning, you were on your own?'

There was a marginal hesitation before she replied. 'Yes. Of course.'

A blast of cold air hit Tartaglia and Feeney as they let themselves out of the building. Tartaglia shivered as he looked up at the leaden sky. More snow was definitely on the way. He turned up his collar against the wind and shoved his hands deep in the pockets of his overcoat.

'So, what do you think?' Feeney asked, as she trailed behind him through the snow and grit on the pavement. Her bushy red hair was tied back as usual, this time in some sort of a half plait, half ponytail concoction. Even though it was still early in the day, it was already starting to unravel, frizzy tendrils escaping like snakes all around her broad, plump face. 'I most definitely got the impression we weren't being given the full story,' she continued in her soft lilting voice, not waiting for his response.

Tartaglia stopped at the edge of the pavement while a line of cars and vans passed them and struggled slowly up the hill. 'She's holding back, I agree. But it could be for a variety of reasons.'

Feeney shook her head vigorously. 'That bit about not having a clue about her best friend's love life well, it's a load of shite, if you want my opinion. Just ask any woman. Doesn't matter if she's been abroad.' She hurriedly smoothed a woolly, pink-gloved hand over the top of her head as she looked questioningly at him.

'I'm sure you're right, but now was not the time to push.'

'Shall we get her into an interview room and make it formal? Maybe then she'd be a bit more willing to cooperate.'

Tartaglia shook his head. 'Not just yet. If there was something material, I think she would have told us. Whatever else she said, or didn't say, I got the impression that she genuinely cared about Rachel Tenison.'

'But why tell such a barefaced lie? Does she think we're idiots?'

There was a gap in the traffic and he led the way through the greying slush, across the road to where their car was parked.

He understood and sympathised with Feeney's frustration and impatience, but you couldn't make someone talk if they didn't want to, and pressure could be counter-productive. After what had happened, it was natural that Liz Volpe wasn't thinking straight. They needed to give her a little time, leave things to sink in properly first. And if that didn't work, they could always try a heavier approach later.

Once at the car, he turned to Feeney. 'I think she's holding back because she's a private person and loyal to her friend,' he said. 'I saw the expression on her face as I kept pressing. She sees it as muckraking and she doesn't yet understand why it's relevant. It's all happened so quickly, she's in shock and she's being defensive. It's only natural. And she doesn't trust us.'

Feeney didn't reply, although he could see from the set of her thin-lipped mouth that she didn't agree.

'We'll get it out of her one way or another, don't you worry,' he added firmly, opening the passenger door and climbing in.

From behind the curtain, Liz watched Tartaglia cross the road, his stride thrusting and purposeful, as if impatient to get on with things. His hands were jammed deep in his pockets and he held his head high, shoulders back. For some reason she thought of Kipling's 'The Cat That Walked by Himself'. The funny little red-haired constable struggled to keep up with him, her oversized mackintosh flapping behind her as she picked her way hesitantly through the snow. What an odd pair they made. They stopped by an ordinary dark blue car, exchanged a few words, then climbed in, the constable taking the driving seat.

Although in some ways the interview had not been as bad as she had been expecting, it had still left a nasty taste. She resented the probing and the pushing almost as if she herself was on trial. And some things were none of their business. She was certain Tartaglia had guessed that she was hiding something, although there was no way he could know what it was. But the more she thought about it, the more uncomfortable she felt.

She watched their car move slowly from its space and then accelerate away up the hill. Once they were safely out of sight, she perched on the arm of the sofa, picked up the phone and dialled a number. After a moment, she heard him answer.

'They've just gone,' she said. 'You wanted me to call you.'

'How was it?'

'Could have been worse, I suppose.'

'Did they give you the third degree?'

She hesitated. 'I think I got off quite lightly. God, I've got such a hangover. I drank myself to sleep last night. And I had such terrible, terrible dreams...all about Rachel.'

'You should have let me come over.'

'No. That wouldn't have been a good idea.'

She realised that her tone had been a little sharp and there was a pause at the other end before he spoke again. 'So, what sort of things did they ask?' His tone was casual, trying to disguise his interest, and it almost made her smile to find him so boyishly transparent for a change.

'They wanted to know about my friendship with Rachel, what she was like, who might have wanted to kill her. You know the type of thing. What could I say? I did my best in the circumstances.'

She tried to make it all sound matter-of-fact and she heard him exhale, possibly with relief, at the other end. She paused, thinking back again to the exchanges with Tartaglia, the way he had looked at her questioningly, trying to read between the lines of what she was saying. That wouldn't be the end of it, she was sure.

'And what did you say?' he asked, now more insistent.

'Just general things, nothing specific.'

'You didn't tell them anything?' She heard the worry in his voice.

'Of course not.'

'You're sure?'

'Of course I'm sure. I know what I said.'

'Good.' Another pause, then: 'Shall I come round later?'

Tartaglia's sharp, dark eyes loomed in her mind, as though he was still watching her. Even though rationally she knew it was a foolish idea he had far better things to do than keep an eye on everybody who had known Rachel she still felt wary.

'Please let me come over,' he said, before she had a chance to reply.

'No. I don't think that's wise.'

'Now you're being melodramatic.'

'Perhaps.' She closed her eyes and pressed her fingers against her temples, as if to block out the image of Tartaglia's handsome face. 'But I don't think it's a good idea. Anyway, I've got a foul headache that won't go away.'

'I can make you better,' he said, softly.

She opened her eyes and gazed blankly at the street below. The centre of the road had been heavily gritted and was a wet, grey slick, with mounds of dirty-looking snow piled up high along the edges and on the sides of the pavement. A bus had come around the corner and had stopped in the middle of the road, unable to pass because of a double-parked car. Traffic was backed up all the way along from the lights at Elgin Crescent and she heard the impatient hooting of horns.

With Rachel's death, something material had changed. She couldn't put it into words, and certainly not to him, but she felt deeply uneasy. She wanted to close her eyes, bury her head in his arms and forget the outside world for a while. But that wasn't the solution, as she well knew; life wasn't that simple anymore.

'Please let me come over,' he said. 'I want to be with you.'

'No. Not tonight. I told you I need some time on my own.'

6.

'Is that a Raphael?' Sam Donovan asked, gazing at the large, ornately framed canvas that hung behind Richard Greville's desk.

A weak smile flickered over Greville's gaunt face. 'Very good, Sergeant, but I'm afraid I must disappoint you. It's a copy, although a very good one, probably painted only a few decades after Raphael's death. We occasionally deal in his drawings upstairs but the oils rarely come up for auction and when they do, they fetch many, many millions. This one, however, came my way a long time ago and I bought it for a song. So I can afford to have it all to myself, wasting away down here, and I'm rather fond of it. It's really rather well done.'

They were in the basement office of the Greville Tenison gallery in Dover Street, Mayfair. The dark red, windowless room smelled strongly of cigar smoke and was lined with books, the only natural light coming from a small lantern skylight in one corner. Greville looked to be in his mid to late fifties, tall and thin, with a mop of lank sandy hair that flopped over his forehead. Dressed casually in a pink oxford shirt, unbuttoned at the neck, and fawn trousers, he was slumped behind his desk in a velvet-cushioned armchair, his face out of range of the dim orbit of light cast by the small, brass reading lamp. It was only mid-morning, but he cradled a cut-glass tumbler of whisky in his hand, stroking the pattern with his long, pale fingers from time to time, as if for comfort.

They had spent the first few minutes discussing his art business in general terms, as Donovan felt Greville appeared to need a gentle preamble before she attempted to question him directly about Rachel Tenison. As they talked, she could hear footsteps on the wooden floor above and the distant murmur of conversation drifting down from the ground floor gallery, where Minderedes was busy interviewing Selina, Greville's pretty, blonde assistant.

'How long have you known Rachel Tenison, Mr Greville?' Donovan asked, glancing at her watch and deciding it was time to move on to specifics.

Greville sighed, screwing up his small blue eyes for a second as if even the mention of her name was painful. 'Over ten years. She worked for me first at Christie's, then we decided to go into business together.' He spoke slowly and deliberately as if every word was an effort.

'Was it an equal partnership? I mean...' Donovan tried to pick her words carefully.

'We owned the gallery fifty-fifty. But what you really mean is, what was a woman like Rachel doing going into business with an old sod like me? It's a fair question. I suppose in those days I had all the contacts and the knowledge and she had the money. But she learned quickly. Soon she had a whole fistful of clients. She was a class act, no doubt about it.' There was no apparent bitterness as he spoke, only a wistful sadness.

'So the relationship between you worked well, you would say?'

He nodded. 'We were complementary. I don't know what will happen now...now she's...gone.'

'You reported her missing on Friday. What gave you cause for alarm?'

'Rachel had a meeting with a client, a very important client. He's an American from Texas who buys a lot through the gallery, and we often bid for him at auctions. She was supposed to see him at his hotel and discuss some things that were coming up for auction. She was then taking him out to lunch and going with him and his wife to the ballet on Friday evening.'

'All that just for a client?'

'It's perfectly normal in our world. We develop close relationships with our collectors and give them the Rolls-Royce treatment when they're in town. It's what brings in the pounds, or in Mr Gunn's case, millions of dollars, all with a nice, healthy commission. Anyway, when Rachel didn't fetch up at Claridge's, I immediately knew something was wrong and I got Selina to phone the police.'

'You didn't phone yourself?'

'I was in Geneva seeing another one of our collectors. That's where I've been until this morning. It was easier to get Selina to call. Apparently it took a while before she spoke to the right person.'

'So you were in Geneva on Friday?'

'That's right. I flew out first thing that morning. I was in the middle of a meeting when Selina called to say that Rachel hadn't come in and she couldn't reach her by phone.'

'You didn't think Miss Tenison was ill?'

Greville shook his head. 'Rachel was never ill. Never. And if she had been, she would have called in. She was like that. As you can imagine, I was really worried.'

'But you carried on with your meetings?'

Greville banged his glass down hard on the desk. 'What else was I supposed to do? The bloody clients wanted to see me. And of course I had no idea what had happened. I heard nothing until later that evening, just before I went to bed, when I picked up a voicemail on my mobile. Someone from the local station said that they had taken a look around her flat no doubt cursory and that nothing appeared to be amiss.' He paused before adding, 'I then called the station myself. They seemed to think it was none of my bloody business if Rachel had decided not to come in to work, that no doubt there was some sort of personal reason why she hadn't turned up. I knew something was wrong but they just wouldn't bloody listen. Told me to call again if she hadn't turned up on Monday.'

He took another slug of whisky and Donovan waited for him to continue. She understood his feeling of impotence and why, in the light of what had happened, he felt bitter. But there had been no justification to send out search parties, particularly after Rachel Tenison's flat had been checked and nothing suspicious found. Even if they had searched the park sooner, by the time the first call from Greville's office was logged, Rachel Tenison was already dead.

'I called several times after that on Saturday and on Sunday,' he added forcefully, as if feeling the need to justify that he had done all he could. 'But I couldn't get hold of the person who had left the message. Kept getting a bloody answer machine and everyone who knew anything about it seemed to have gone home. Then somebody telephoned me last night and told me Rachel was dead. That her body had been found in Holland Park.' He put down his glass and rubbed his face with his hands, shaking his head as if he still couldn't believe what had happened. 'I somehow feel I should have been here, in London. Perhaps I should have flown back sooner...'

'If it's any consolation, we believe Miss Tenison was killed early on Friday morning.' He stared at her blankly and she repeated herself: 'Even if you had got more of a response from the local station, there was nothing that you or anyone else could have done, I assure you.'

He nodded slowly, grimacing, and drained his glass as if disgusted with the whole process. 'Don't normally drink like this,' he said, putting the glass down firmly on the desk in front of him. 'Certainly not in the morning. But I haven't slept. Don't think I'll get much work done today. I'll probably close the gallery and go home after you've gone. Need to get my mind around what's happened. Work out what's to be done, how I'm going to tell the clients.'

His grief and shock seemed genuine and she wished she didn't have to trouble him further. 'Can you think of any reason why somebody might have wanted to kill Miss Tenison?' she asked, after a moment.

He looked up at her and blinked. 'No. Everybody adored her. That's how she was. Rachel could charm absolutely anyone.'

'There's nothing you know of, in her work or personal life, that might have threatened her in any way?'

'No. Nothing.' He frowned. 'Surely it's simple. There's some bloody nutter on the loose, some sick maniac let out of jail or hospital because the government won't pay to keep them locked up where they belong.'

'We're considering all possibilities, Mr Greville,' Donovan said, not wishing to be drawn into a political discussion, although she sympathised. 'And one of them is that she was killed by someone she knew.'

He shook his head vigorously. 'Why would anyone who knew Rachel want to kill her? It doesn't make sense.'

'What about one of her clients? As you say, the relationships sound quite close. Couldn't one of them have crossed the line?'

'No. Nobody I can think of, at any rate. Of course, some of them probably found her attractive. It's part of life and she was a very pretty girl. But Rachel was incredibly careful about things like that, never went too far, always kept firm boundaries. The clients knew that and respected her for it. She was always completely professional.'

'What about her personal life?' She caught his eye, wondering if he would bring up his relationship with Rachel Tenison voluntarily.

Greville looked surprised. 'You think this was a crime of passion?' He rubbed his chin thoughtfully for a moment before saying, 'Can't think of anything recent. There was a fellow at Christie's who used to follow her around a bit like a lost lamb, but I don't think she was at all interested. No idea what happened to him, and he was so wet you could wring him out...he's hardly the type...Anyway, it wasn't anything meaningful, if that's what you're looking for. She used to have lunch with the occasional friend but that's all.'

'Was there anyone else?'