‘Sorry, Miss. You can’t come in here.’

‘Where’s Detective Inspector Wilson?’

Constable McGonigle was surprised.

‘Upstairs, Miss.’

‘Good,’ she said.

Her fair hair shone white in the darkness and Constable McGonigle could smell her perfume. She lifted a silken leg and straddled his yellow tape.

‘I’d better go on up then,’ she said.

The click of Rhona’s heels echoed round the grimy stairwell, but if she was disturbing any of the residents, they didn’t show it by opening their doors. No one here wanted to be seen. If there was a fire they might come out, she thought, in the unlikely event they weren’t completely comatose.

A door on the second landing stood ajar. She could hear DI Wilson’s voice inside. If Bill was here at least she wouldn’t have to explain who she was. She could just get on with the job, go home and crawl back into bed.

The narrow hall was a fetid mix of damp and heat. The sound of her heels died in a dark mottled carpet, curled at the edge like some withered vegetable. She paused. Three doors, all half open. On her right a kitchen, on her left a bathroom. She caught a glimpse of a white suit and heard the whirr of a camera. The Scene of Crime Officers were already at work.

The end door opened fully and Detective Inspector Bill Wilson looked out.

‘Bill.’

‘Dr MacLeod.’

He nodded. ‘It’s in here.’

He allowed himself a tight smile. The two other men in the room turned and stared out at her. Dr MacLeod was not what either of them had expected.

Rhona looked down at her black dress and high-heeled sandals. ‘I came out in a bit of a hurry.’

‘McSween will get you some kit.’

Bill nodded to one of the men, who went out and came back minutes later with a plastic bag.

Rhona pulled out the scene suit and mask, put her coat into the bag and handed it to the officer. She took one shoe off at a time and, hitching up her skirt, slipped her feet into the suit. Only then did she step inside.

Rhona took in the small room at a glance. The hideous nicotine-stained curtains stretched tightly across the window. A wooden chair with a pair of jeans and a tee-shirt thrown over it. Two glasses on a formica table. A pair of trainers on the floor beside the bed. A divan, three-quarters width, no headboard but covered with heavy silken brocade in an expensive burst of swirling colours.

The boy’s naked body lay face down across it, his head turned stiffly towards her, eyes bulging, tongue protruding slightly between blue lips. The dark silk cord knotted round the neck looked like a bow tie the wrong way round. The body showed signs of hypostasis, and the combination of dark purple patches and pale translucence reminded Rhona of marble. Below the hips blood soaked into the bedclothes.

‘I turned the gas fire off when I arrived,’ Bill said. ‘The smell nearly finished off our young Constable, so I put him on duty outside for some fresh air.’