'Go on.'

She was watching me closely, and I found myself watching her back. She had beautiful brown eyes that seemed to swallow you up. Not for the first time I found myself wondering what the fuck she was doing managing a children's home.

'I ran into one of your clients this evening. Anne. She was in the middle of being abducted by one of her prospective customers.'

She looked genuinely concerned. 'Is she all right?'

'Yeah, she's all right. But she was lucky, Ms Graham. If I hadn't been there, I don't know what would have happened. Somehow I don't think it would have been a happy ending.'

'These girls…' She shook her head slowly. 'There's no telling them. It's as if they've got a death wish.'

'Well, it could be a wish that ends up being fulfilled.'

'I know, I know. What's so tragic about the whole thing is that Anne's got so much intelligence. She could really do something with her life if only she'd listen to people. Where is she now?'

'I took her back to your place. That's when I came in to see you.'

'You should have told me.'

'Don't worry. She's OK. She took it remarkably well. We talked for a while afterwards and she seemed concerned, particularly about Molly Hagger's disappearance. She seemed to think that Molly didn't just walk out-'

'What did she think had happened to her?'

'She wouldn't say for sure, but I think she felt something untoward had happened.' I briefly explained the reasons Anne had given me, without mentioning Mark Wells by name. When I'd finished I had to admit to myself that they sounded pretty flimsy.

Carla took a packet of Silk Cut out of her handbag and put one in her mouth, before realizing that she hadn't offered me one, and hastily pointing the pack in my direction.

I declined. 'My throat demands something stronger,' I said, taking a pack of Benson & Hedges out of my shirt pocket.

She lit my cigarette for me and I got a vague but pleasant smell of her perfume as I leaned forward.

'I thought you said you'd arrested someone for the girl's murder.'

'We have, and we're questioning him very closely, but we have to keep our options open. It might be that he's also responsible for murdering Molly Hagger. It might be that he's not responsible for anything.'

She took an elegant draw on her cigarette. 'Do you think she's dead?' she asked.

'I don't know. Anne was adamant that Molly Hagger would never have gone away of her own accord, but she could well be wrong.' I paused, then decided to jump in at the deep end. 'You can't think of any other girls who've left the home in the last few months who, perhaps, you didn't expect to lose?'

Carla gave me a reproachful look. 'Mr Milne, I understand your concerns, and I sympathize with them. If anything's happening to young girls it's essential it gets uncovered, but, with due respect, not every female client at Coleman House is a teenage prostitute. Some get involved in that sort of thing, I won't deny that, but they're in a minority, and we certainly don't keep the streets of King's Cross stocked up with underage girls. There are dozens of care homes in a three-mile radius of here who have exactly the same problems as we do. Do you really think it's likely that our clients are being picked off one by one by some unknown murderer?'

'No, no, of course not. I'm sorry if it came across like that. I'm just trying to look at every avenue.' I took a sip of my drink, noting that hers was getting dangerously near to the bottom of the glass. I didn't want her to go – not yet – but I wasn't doing too well at charming her into staying. 'Will you do me a favour, though? Just to indulge me.'

'What?'

'Will you just let me know if any of your clients absconds, or goes missing under suspicious circumstances? Please. Anything you say will be treated with the utmost confidentiality.'

She nodded. 'All right, but we get that happening a lot of the time, as I said to you and your colleague yesterday. Most of the time, it's just that. Them absconding. Looking for greener pastures. It's the same for all the homes, especially in a city the size of this one.'

'Yeah, I know. That's the problem. If you were, say, a killer, and you didn't want to get caught, they're just the type of girls you'd go for. Ones who can disappear without a trace and no-one's too worried.'

'But I do worry – we all worry – for our clients because we know the pitfalls that await them round every corner. But without resources, and without authority…'

'Yeah, I know. What can you do?'

'Exactly. But if any of the girls goes missing, I will let you know.'

'Thanks. I appreciate it.' I took a drag on my cigarette, knowing I had to do something to keep the conversation alive if I was going to keep her here. 'It seems ridiculous that these kids can just do exactly what they want when they're so, you know, unequipped for life.'

'It's a debate we have constantly within the profession,' she said. 'It goes against the grain for many of us to take authoritarian measures, but sometimes I genuinely feel there's no alternative. These children are vulnerable, they just don't know it.'

'It's funny,' I said, not wanting to lose the moment, 'but when I was a kid, my mum used to tell me what a cruel world we lived in. She always said enjoy everything while you're young, but be prepared, because when you get older you'll see that there are a lot of bad people out there. And you know what? I never believed her.'

'But you do now?'

'Yeah, I do now. If anything, she was more right than she could have known.'

'You're beginning to strike me as the sensitive type, Mr Milne.'

'I'm not quite sure whether I should take that as a compliment or not.'

She thought about that for a moment, looking at me over her glass. 'Take it as a compliment. It's how it was intended.'

'We're not all fascist bullyboys, you know. Some of us are actually quite nice people – especially when we're not at work.'

'I don't doubt it. And just because I'm in the profession I'm in, it doesn't mean I'd automatically think you were all fascist bullyboys.'

'But some of your colleagues do.'

'Some of the younger ones do, yes. When I first joined social services, I was probably a lot more black and white in my view of the forces of law and order too. But that was a long time ago.'

'Not that long, I'm sure,' I said with mock chivalry.

She smiled. 'Now that I will definitely take as a compliment.'

'It's how it was intended.'

She looked at her watch, then back at me. 'I really ought to be going, Mr Milne. Time's getting on, and I'm driving.'

'Well, have one last drink with me. It's a rule I've got that I always have to have a minimum of two drinks in every pub I go into. One drink means you're in too much of a hurry.'

'It's an interesting theory. All right, then, I'll have one more. But let me buy.' She stood up. 'Same again?'

'Please.'

I watched her as she walked across to the bar. She was wearing black high-heeled boots and she carried herself extremely well, moving with a grace I would normally associate with a model. Or maybe it was just me. I was already fully aware that I had the hots for her. I expect she knew it too, but it was only watching her then that I realized quite how much I wanted to rip her clothes off and make love to her on the spot. It had been close to six months since I'd last had sex so it wasn't going to take a lot to get me going, and the last time had been no great success either. On that occasion it had been a woman DC from the station who'd been as drunk as me, so it was never going to be a match made in heaven. She'd been engaged to a lawyer from the CPS and I'd got so worn out that I'd had to fake an orgasm. Twice. Although I must have done something right because she'd wanted to see me again afterwards.