'Fine. And Ted Barlow rang to ask if you'd made any progress.'

Tell him I'm pursuing preliminary inquiries and I'll get back to him when I have something solid to report. And are you?'

'Am I what?' Shelley sounded genuinely baffled. That must have been a novel experience for her.

'Making any progress.'

'As I'm always having to remind my two children,” heavy emphasis on the 'children', 'there's nothing clever about rudeness.'

'I'll consider my legs well and truly smacked. But are you?'

'That's for me to know and for you to find out. Goodbye, Kate.' I didn't even have time for the goodbye before the line went dead.

It was just before twelve when I managed to find someone who could give me any useful information about my missing conservatories. But when I did, it was worth the wait. Diane Shipley was every private investigator's dream. She lived at the head of Sutcliffe Court, her bungalow commanding a view of the whole close. With a corner of my brain, I had noted the raised flower beds and the ramp leading up to the front door, but it still didn't stop me having my eyes at the wrong level when the door opened. I made the adjustment and found myself staring down into a face like a hawk; short, salt and pepper hair, dark beady eyes, deep set and hooded, narrow nose the shape of a puffin's beak, and, incongruously, a wide and humorous mouth. The woman was in a wheelchair, and it didn't seem to bother her in the slightest.

I delivered my usual spiel about the house next door's conservatory, and her face relaxed into a smile. 'You mean Rachel Brown's conservatory?' she inquired.

I checked my list. 'I've got Rowena and Derek Brown,' I said.

'Ah,' said the woman. 'Dirty work at the crossroads. You'd better come in. My name's Diane Shipley, by the way.'

I introduced myself as I followed her down the hall. We turned left into an unusual room. It ran the whole depth of the house, with windows on three walls, giving a sensation of light and air. It was painted white, with cork-tiled flooring. The walls were decorated with beautifully detailed drawings of flowers and plants. Across one corner was a draughtsman's table, set at the perfect height for her chair. 'I illustrate children's books for a living,' she said. The other stuff I do for fun,' she added, gesturing at the walls. 'In case you were wondering, I had a riding accident eight years ago. Dead from the waist down.'

I swallowed. 'Right. Em, sorry about that.'

She grinned. "That's not why I told you. I find that if I don't, people only concentrate on half of what I'm saying because they're so busy wondering about my disability. I prefer a hundred per cent attention. Now, how can I help you?'

I trotted out the old familiar questions. But this time, I got some proper answers. 'When I'm working, I tend to do a fair bit of staring out of the window. And when I see people in the court, I must confess I watch them. I look at the way their bodies move, the shapes they make. It helps when I'm drawing action. So, yes, I noticed quite a lot about Rachel.'

'Can you describe her?'

Diane wheeled herself across to a set of map drawers. 'I can do better than that,' she said, opening one and taking out an A4 file. She shuffled through the sheets of paper inside, extracted a couple and held them out to me. Curious, I took them from her. They were a series of drawings of a head, some quite detailed, others little more than a quick cartoon of a few lines. They captured a woman with small, neat features, sharp chin, face wider across the eyes. Her hair was shoulder-length, wavy. 'It was streaked,' Diane said, following my eyes. T wondered a couple of times if it might be a wig. It always looked the same. Never looked like she'd just been to the hairdresser. If it was a wig, though, it was a good one. You couldn't tell, not even face to face.'

'How well did you know her?' I asked.

'At first, not at all. She didn't spend that much time here. It was May when she moved in, and really, she was only here perhaps three or four nights a week, Monday to Friday. She was never here at weekends. Then, one evening in June, she came over. It was about half past nine, I'd guess. She said she had a gas leak and she was waiting for the emergency engineers. She told me she was nervous of staying in, especially since they had told her not to turn any lights on. So I invited her in and gave her a drink. White wine. I had a bottle open already'

I loved it. A witness who could tell me what she'd had to drink four months before. 'And did she tell you anything about herself?'

'Yes and no. She told me her name, and I remarked on the coincidence. She said yes, she had noticed when she exchanged contracts to buy the house that she had the same name as the vendors, but she'd got used to that kind of coincidence with a name like Brown. I was a little surprised, because I had no idea that Rowena and Derek had actually sold the house.'

I had that feeling you get when you walk into a theatre halfway through the first act of a new play. What she was saying made perfect sense, but it was meaningless unless you'd seen the first twenty minutes. 'I'm sorry, you're going to have to run that past me a little more slowly. I mean, surely you realized they'd sold the house when they stopped living there and a new person moved in?'

It was her turn to give me the baffled look. 'But Derek and Ro haven't lived in the house for four years. Derek is an engineer in the oil industry, and he was away two weeks in four, so Ro and I got to be really good friends. Then, four years ago, Derek was offered a five-year contract in Mexico with a company house thrown in. So they decided to rent out their house over here on a series of short-term lets. When Rachel moved in, I thought she was just another tenant till she told me otherwise.'

'But surely you must have realized the house was up for sale? I mean, even if there wasn't an estate agent's board up, you can't have missed them showing people round,' I remarked.

'Funny you should say that. It's exactly what I thought. But Rachel told me that she'd seen it advertised in the Evening Chronicle, and that she'd viewed it the next day. Perhaps I was out shopping, or she came after dark one evening when I wasn't working. Anyway, I saw no reason to doubt what she was telling me. Why lie about it, for heaven's sake? It's not as if renting a house is shameful!' A laugh bubbled up in Diane's throat.

'Was she on her own, or was she living with someone?' I asked.

'She had a boyfriend. But he was never there unless she was. And he wasn't always there even if she was. I tended to see him leave, rather than arrive, but a couple of times, I saw him pay off a taxi around eleven o'clock at night.'

'Did he leave with Rachel in the mornings?' I couldn't see how this all fitted together, but I was determined to make the most of a co-operative witness.

Diane didn't even pause for thought. 'They left together. That's why I don't have any drawings of him. She was always between me and him, and he always got in the passenger side of the car, so I never really got a clear view of him. He was stylish, though. Even at a distance I could see he dressed well. He even wore a Panama hat on sunny mornings. Can you believe it, a Panama hat in Urmston?'

Like cordon bleu in a motorway service station, it was a hard one to get my head round. 'So tell me about the conservatory.'

This time she did take a moment to think. 'It must have been towards the end of July,' she said slowly but without hesitation. 'I was away on holiday from the first to the fifteenth of August. The conservatory went up a couple of days before I left. Then, when I came back from Italy, they'd all gone. The conservatory, Rachel Brown and her boyfriend. Six weeks ago, a new batch of tenants arrived. But I still don't know if Rachel has let the house, or indeed if Rachel ever bought it in the first place. All I know is that the chaps in there now rented it through the same agency that Derek and Ro used, DKL Estates. They've got an office in Stretford, but I think their head office is in Warrington.'