Browne peered at him thoughtfully over her glasses. 'That's not straightforward either. There are restraint marks on the inside of her arms where she was held down, as well as chafe marks and swelling around her ankles and wrists consistent with her having been secured in some fashion. They weren't caused by the duct tape but by something more abrasive. Again, allowing for the development of the bruising and swelling, this was all several hours before death.'

'Could it have been some kind of rope?'

'No. Something harder and sharper. I'd hazard a guess that she was handcuffed.'

'Which goes along with the idea of rape.'

Browne nodded. 'The lack of swelling immediately around the tape at the wrists and ankles would suggest that she was either dead or very close to death when the tape was used.'

Still puzzled, he thought back again to Rachel Tenison's flat. 'There weren't any signs of a struggle or assault at her flat. Maybe she was killed somewhere else, then trussed up with the duct tape and dumped sometime later in the park, although how the hell you lug a body into the middle of the park without being seen beats me. And why go to the trouble?'

Browne gave him a level stare. 'I wouldn't like to speculate.'

Short of any immediate insight as to what might have happened, he was about to ask her to give it a try anyway, when his phone rang. It was Donovan.

'I've managed to get hold of the stepbrother, Patrick Tenison,' she said. 'He was on his way back to London from his constituency, where he lives. He says he'll meet you at his flat in an hour.'

Patrick Tenison's flat was on the top floor of a tall, converted nineteenth-century building in Westminster, close to the Houses of Parliament. Tenison buzzed Tartaglia in and was waiting for him in the doorway of his flat as Tartaglia climbed out of the lift. Casually dressed in brown cords and an open-necked checked shirt, he was tall and well built, with a broad face and very short dark hair. Tartaglia recognised him immediately as an older version of the man in the photograph in Rachel Tenison's flat.

He held out his hand to Tartaglia. 'Please come in, Inspector. Is it snowing again?' He glanced at Tartaglia's wet leather jacket and helmet as he ushered him into the cramped hallway beyond.

'Just started as I was leaving. It's coming down quite heavily now.'

'You can hang your things up there to dry, if you want.' Tenison pointed to a set of pegs by the front door. 'Doesn't matter if they drip on the floor. The carpet needs replacing, if only the landlord would get around to it.'

Tartaglia put his helmet on the floor and unzipped his jacket. Removing a pen and notebook from the pocket, he gave the jacket a shake and hung it up. He followed Tenison into a small, low-ceilinged sitting room at the back. A tray of drinks stood on a small table in a corner of the room from which Tenison was mixing himself a large brandy and soda.

'Can I get you something?' Tenison's voice was flat, without energy.

'I'm fine, thank you.' Tartaglia sat down in an armchair and gazed around at the cramped interior.

The room was furnished with dull prints, reproduction furniture and plain, oatmeal-coloured carpet. It looked like a cheap corporate let and not somewhere that Tenison spent much time, judging by the lack of any books or personal belongings. A pair of small windows was set into the eaves, and through the open blinds Tartaglia could see the glittering lights and outlines of the buildings along the Thames as well as the London Eye.

'Can you tell me what happened?' Tenison asked, coming over to Tartaglia with his glass and lowering himself into one of the armchairs opposite. 'The police who came to my house...They said her death is suspicious, that she was strangled. They said she was found in Holland Park.' He spoke quietly, enunciating each word precisely as if trying to control his speech. He put the glass to his lips and drained it in three gulps.

'That's right,' Tartaglia replied guardedly. 'Do you have any idea what she might have been doing there? It's only a stone's throw from where she lived, so I wondered...'

'She used to go running there most mornings. She loved the park. It's why she bought that flat.'

It corroborated what Liz Volpe had said and Tartaglia made a note. 'She'd go running even in bad weather?'

'Particularly in bad weather. She liked to have the park to herself.' Tenison put down his empty glass and rubbed his eyes. 'You know, it's funny. I always warned her about running alone. I told her it was dangerous, but she paid no attention to me.' He looked up, his brown eyes searching Tartaglia's face. 'What happened?'

'I'm sorry, but I can't give you any more details at the moment.'

'You must be able to tell me something.' Tenison was still staring at him. 'Was she...Was she assaulted? Was it sexual?'

'I really can't tell you anything further now,' Tartaglia said firmly. Tenison's desire to know more was only natural, but the less he, or anyone else close to Rachel Tenison, knew about the details, the better. Everyone in her immediate circle of family and friends was under suspicion, until alibis could be confirmed.

'I see,' Tenison said, frowning as though he didn't appreciate the lack of clarity. 'Do you have any idea who did it?'

'It's far too early to tell, Mr Tenison. It's one of the reasons I'm here. Am I right in thinking that you're Miss Tenison's next of kin?'

Tenison gave a slight nod. 'I'm actually her stepbrother. My father married her mother when Rachel was three and Rachel took our family name.'

'Are they still alive?'

He shook his head. 'They were both killed in a car crash when Rachel was twelve. I was living with my mother at the time. She offered Rachel a home as there was nowhere else for her to go.' Tenison spoke dispassionately, as though he was a third party observer, but everyone dealt with shock in different ways. Tartaglia had the impression that his detached manner was just a mechanism for keeping himself in check.

'Nowhere? What about Rachel's father?'

'She never knew him. He walked out on Rachel's mother just after Rachel was born and that was the last they heard of him. He never got in touch. He could be dead too, for all I know.'

Coming from a large and extended close-knit family, all of whom would have welcomed him with open arms in similar circumstances, Tartaglia was moved by the thought of a twelve-year-old girl left completely on her own in the world apart from a stepbrother and his mother. Again he thought of Rachel Tenison as he had found her, so fragile and broken, and felt a pang of intense sadness along with a sudden, irrational desire to protect her, even in death.

'We will need you to identify her body,' he said, his eyes still on Tenison's leaden face.

Tenison nodded. 'Whatever I can do to help.'

'Can you think of any reason at all why someone might have wanted to kill your sister, Mr Tenison?'

Tenison closed his eyes for a second, then shook his head with a sniff. 'Rachel was a very special, very talented woman,' he said with sudden feeling. 'She had no enemies. Everyone who knew her loved her.'

'What about her friends? Is there anyone she was particularly close to?'

'You should speak to Liz. Liz Volpe. She has known Rachel the longest. They went to the same school, from the time Rachel came to live with us.'

'Anyone else?'

Tenison sighed. 'Most of Rachel's other female friends are married and have families. Their lives went in different directions and a couple moved out of London. Rachel was a godmother to a few of their children, but I get the impression she didn't see them that often.'

'So who did she see? I presume she didn't stay at home all the time.'

'Rachel put most of her energies into her work, Inspector. Her business was like a marriage or a surrogate child, if you like. It didn't leave much time for anything else.'

'She was successful?'

'Very.'

'I hope you won't mind my asking, but from what I've seen, Miss Tenison seems to have been a wealthy woman.'

'She inherited some money and property from her mother, all of which she ploughed into the business. She worked incredibly hard and the business has done well. They're now one of the top dealers in Old Master paintings in London.'

'Do you know the name of her solicitor?'

Tenison looked puzzled. 'You think somebody did this for money?'

'At this stage, we have no idea. You know the cliche we have to look at every angle.'

Tenison nodded slowly. 'Crowther and Phillips, in Lincoln's Inn Fields, but I can save you the trouble of speaking to them. I'm Rachel's executor. Apart from a few small charitable bequests, she left her shares in the business to Richard Greville, her business partner. Her flat and most of the contents, bar family stuff, go to Liz Volpe. The rest of her assets are to be placed in trust for my two children, James and Lorna.'

'She left nothing to you?' he asked, surprised, as he jotted down the details.

'That was the way I wanted it.' Tenison compressed his lips as though he had no desire to discuss it further.

'Did any of the beneficiaries know about the contents of Miss Tenison's will?'

'Look, Inspector,' he said emphatically, leaning forwards, elbows on his knees. 'None of them would kill Rachel for the money.'

'Please answer the question, Mr Tenison. I have to check everything, tick all the boxes.'

Tenison sighed and leaned back again into the sofa. 'All right. For what it's worth, I'm pretty sure they don't know. Rachel was a very private person and she would keep that sort of thing to herself. Anyway, why would she tell them? It wasn't as if she thought she was going to die. It was supposed to be just a sensible precaution. Neither of us dreamt it would ever come to this.'

'When was the will drawn up?'

'A couple of years ago. The chap at Crowther and Phillips will be able to tell you precisely when.'

Tartaglia made a note to get someone to check. 'Would you describe your relationship with Miss Tenison as close?'

The question seemed to surprise Tenison and he took a moment to answer. 'Yes, we were close. Very close.' With a sigh, he got to his feet and walked over to the window, gazing sightlessly outside. He seemed physically drained, as though the stuffing had been knocked out of him. For such a big, powerful-looking man, the impression was striking. 'I have no other brothers or sisters and neither did she,' he said. 'I'm seven years older, but there was a real bond between us which grew over the years, although we never really lived in the same house together for long. I've always felt very protective of her. She was such a pretty, fragile little thing when she came to us. She would barely speak or offer an opinion and she hated leaving the house, as though something terrible might happen. It used to drive my mother mad.'

'But you cared about each other?' Tartaglia asked quietly.

'Yes. Very much so. I...' Tenison's voice tailed away and he rubbed his face vigorously with his hands.

'You saw quite a lot of each other?'

With a snort, Tenison turned around to face Tartaglia. 'We had several mutual friends. She introduced me to my wife, Emma. They were at university together.'

'Where is your wife, Mr Tenison?'

'In Hampshire. We have a house in my constituency. She lives there full time with our children. I only come up to London for work.'

'She was there last Friday?'

'As far as I know. Is that when you think-'

'Again, we're not sure yet. Miss Tenison was reported missing Friday afternoon by someone in her office. The last time they saw her was around six o'clock Thursday evening. We will obviously try and establish her movements afterwards, but given what you've told me about her habit of running in the park in the morning, it seems we're looking at her being attacked on Friday. Can you please tell me what your movements were that day.'

Tenison looked at him astounded. 'Me?'

'These are just routine things we have to ask everybody we speak to.'

He gave a weary sigh. 'Of course. I'm sorry. I suppose you have to check, don't you? Friday? Well, I was here on my own, obviously until about eight. I then caught a train down to Hampshire and I was in meetings for most of the day. I've been out of London until now.'

Tartaglia made a note. Once they had a more precise idea of the chronology of events and an estimate for time of death, they would check everything thoroughly. 'Going back to the issue of motive, did Miss Tenison ever discuss her relationships with you?'

'What, with men?'

'Yes.'

'Not really.'

'But she had relationships?'

'Nothing serious that I'm aware of, certainly not recently.'

'Forgive me, Mr Tenison, but your sister was in her thirties and she was an attractive woman. There must have been somebody at some point in her life. She must have had lovers.'

Tenison stared at him without speaking.

'It's very important,' Tartaglia added.

'OK, Inspector. I take your point.' He came back to the sofa and flopped down, legs stretched out in front of him. 'Have you spoken to Richard Greville?'

'Her business partner? He's been contacted but he's abroad.'

'They had a long affair, if you can call it that. Richard used to be her boss at Christie's. They got along so well, so to speak, that they left to set up the business together.'

'But it's over?'

'Yes. From what I know, it finished a while ago.'

'Was it a serious relationship?'

'At one point, I think so. Problem was, Richard was already married.'

'He wouldn't leave his wife?'

'No. Anyway, I'm not sure Rachel would have wanted him to.'

'What do you mean by that?'

Tenison frowned, as though he had said something out of turn. 'I think she was happy with the way things were, that's all.'

Tartaglia felt there was more behind Tenison's words, but now was not the time to probe. 'And Richard Greville?'

Tenison shrugged. 'Who knows. I doubt Rachel was his first affair, or his last. He's been married to Molly for twenty years or so and he's quite dependent on her, in a funny sort of way. She gives him the security and bolstering he needs so that he can play around. Rachel would never have done that for him.'

'Who broke off the relationship?'

'Rachel, I imagine, although there were no fireworks, as far as I'm aware. The affair had just run its course.'

'Was Greville bitter about it?'

'Not that I know of.'