The bin-bag the girl was stuffed into came from the home of Norman Chalmers. Only there was no forensic evidence to tie him to the victim. Other than the contents of the bag. Maybe that was enough to go to trial, but a good defence lawyer – and Sandy Moir-Farquharson wasn't just good: the little shite was brilliant – would rip the case to shreds.

'Right.' He sat back on the desk, arms folded, staring at the two pins in the map.

That bin-bag bothered him. The flat had been covered in cat hair when they'd arrested Chalmers. Logan had spent most of that night in the pub trying to brush the damned stuff off his trousers. There were still stubborn patches of grey fluff sticking to his suit jacket. If the kid had been in the flat, Isobel would have found traces of cat hair during the post mortem.

So she was never in the flat. That much they knew. That was why Insch had asked for a thorough background search on Chalmers, to see where else he could have taken her. But the research teams had come up empty. If Norman Chalmers had somewhere else to take a four-year-old girl, no one knew about it.

'So what if he didn't do it?' he asked himself aloud.

'What if who didn't do what?'

It was WPC Wat…Jackie.

'What if Norman Chalmers didn't kill that little girl?'

Her face hardened. 'He killed her.'

Logan sighed and picked himself off the edge of the desk. He might have known she'd be touchy about this. She was still hoping that finding the receipt would crack the case.

'Look at it this way: if he didn't kill her someone else did. OK?'

She rolled her eyes.

Logan went on quickly. 'OK, so if it was someone else it has to be someone who's got access to Norman Chalmers's rubbish.'

'No one does! Who's going to get into his rubbish?'

Logan poked a finger at the map, making the paper crackle. 'Rosemount has those big communal bin things out in the street. Anyone could dump their crap in one. If the killer wasn't Chalmers, then there's only two places they could get the body into that bin-bag: here-' he poked the map again, '-or here, when it gets to the tip at Nigg. If you're going to hide a body at the tip, you're not going to leave a leg sticking out. What would be the point of that? Much easier to just bury it in the rubbish bags.' Logan pulled the Nigg pin out of the map and tapped the red plastic end against his teeth. 'So, the killer didn't dump the body at the tip. It was taken there in the back of a corporation dustcart and poured out the back along with all the other junk. She was put in that bin-bag while it was still out in the street.'

WPC Watson didn't look convinced. 'Chalmers's flat is still the most logical. If he didn't kill her, why's she in a bin-bag along with his garbage?'

Logan shrugged. That was the problem. 'Why do you put anything in a bag?' he asked. 'To make it easier to carry. Or to hide it. Or…' He turned back to the table and began sorting through the statements the door-to-door team had taken. 'You're not going to cart a dead girl round in your car looking for a wheelie-bin to stuff it in,' he said, putting all the statements into piles according to their house number in Wallhill Crescent. 'You've got a car: you take the body away and bury it in a shallow grave out by Garlogoie, or up round New Deer. Somewhere isolated. Somewhere no one's going to find it for years and years. If ever.'

'Maybe they panicked?'

Logan nodded.

'Exactly. You panic: you get rid of the body in the first place you can find. Again, you don't go driving round looking for a wheelie-bin. The fact she wasn't wrapped in anything other than packing tape is weird too. A naked little dead girl, all stuck together with brown packing tape? You're not going to go far carrying that…Whoever dumped the body lived nearer this particular bin than any of the others in the street.'

He split the piles of statements into two, those within two doors of number seventeen and those farther away. That still left thirty individual flats.

'Can you do me a favour?' he asked, scribbling down the names from each statement onto a fresh sheet of paper. 'Get these down to Criminal Records. I want to know if any of them have priors for anything. Warnings, arrests, parking violations. Anything.'

WPC Watson told him he was wasting his time. That Norman Chalmers was guilty as sin. But she took the names away with her and promised to get back to him.

When she was gone Logan grabbed a bar of chocolate from the machine and a cup of instant coffee, consuming both while he read through the statements again. Someone here was lying. Someone here knew who the little girl was. Someone here had killed her, tried to cut up her body, and thrown her out with the trash.

Trouble was, who?

Over three thousand people went missing in the north-east of Scotland every year. Three thousand people reported missing every twelve months. And yet here was a four-year-old girl missing for at least two days now, according to the post mortem, and no one had come forward to ask what the police were going to do about it. Why hadn't she been reported missing? Maybe because there was no one to notice she was gone?

The familiar jangling tune blared out from his pocket and Logan swore. 'Logan,' he said.

It was the front desk telling him he had a visitor downstairs.

Logan scowled at the pile of statements sitting on the desk. 'OK,' he said at last. 'I'll be right down.'

He dropped his chocolate wrapper and empty plastic cup into the bin and headed down to the reception area. Someone had cranked the heating up too far and the windows were all fogged up as visitors, drenched in the downpour outside, sat and steamed.

'Over there,' said the pointy-faced desk sergeant.

Colin Miller, the Press and Journal's new golden boy from Glasgow, was standing over by the wanted posters. He wore a long black tailored raincoat that dripped steadily onto the tiled floor while he copied down details into a small palm computer.

Miller turned and grinned as Logan approached. 'Laz!' he said, sticking out a hand. 'Good tae see you again. Love what you've done with the place.' He swept a hand round to indicate the steamy, cramped reception area with its soggy visitors and steamy windows.

'My name's DS McRae. Not "Laz".'

Colin Miller winked. 'Oh, I know. I've done me some diggin' since we met in the bogs yesterday. That wee WPC of yours is a bit tasty, byraway. She can bang me up any time, if you know what I mean.' He gave Logan another wink.

'What do you want, Mr Miller?'

'Me? I wanted tae take my favourite detective sergeant out for lunch.'

'It's three o'clock,' said Logan, suddenly aware that, except for a bar of chocolate and a couple of butteries, he'd not had a thing to eat since WPC Watson's bacon buttie this morning. And he'd left that splattered all over the grass at Roadkill's house of horrors. He was starving.

Miller shrugged. 'So it's a late lunch. High tea…' He cast a theatrical eye round the reception and dropped his voice to a conspiratorial whisper. 'We might be able to help each other out. Could be I know somethin' you could use.' Miller stood back and beamed again. 'What d'you say? The paper's buyin'?'

Logan thought about it. There were strict rules about accepting gifts. The modern police force was at great pains to make sure no one could point the finger of corruption in their direction. Colin Miller was the last person he wanted to spend more time with. But then again, if Miller did have information…And he was starving.

'You're on,' he said.

*

They'd found a corner booth in a little restaurant down in the Green. While Miller ordered a bottle of chardonnay and the tagliatelle with smoked haddock and peppers, Logan contented himself with a glass of mineral water and the lasagne. And some garlic bread. And a side salad.