What had been retrieved so far suggested that Olivia, if that was indeed her name, had not chosen this end willingly, rather that someone or something had driven her to it.

The incessant tugging at the tent by the wind had ended. Now it was only the softly insistent patter of rain on the roof. Rhona quietly thanked whatever deity had allowed the back court to be properly searched before the rain had taken over from the wind.

At that point she heard Chrissy’s voice and the tent flap being pulled back.

‘You’d better come and see this.’

Rhona followed her assistant into the close and up the stairwell. All the doors they passed on the way remained closed, although she suspected that whatever was happening out here was being closely followed by the occupants of the other flats.

The left-most door on the top landing stood open, and by its state it was obvious it had been forced. Rhona could hear McNab’s voice coming from inside. She followed Chrissy in, moving carefully from tread to metal tread, the presence of which already declared it to be a possible crime scene.

Rhona mentally prepared herself for what might come next. At the far end of the narrow hallway stood a still-suited and masked McNab guarding an open doorway. At her approach he stepped to one side to allow her entrance.

It was a bedroom and the smell of petrol came, she suspected, predominantly from the stained and rumpled bedding. The mattress sat in a metal frame, the top and bottom of which gave ample opportunity for attaching a captive’s wrists and ankles via cable ties.

Chrissy confirmed this by holding up a clear evidence bag with the apparent remains of the ties inside.

‘Any sign of the petrol can?’ Rhona said.

‘Not in here, or anywhere else in or outside the building.’

‘So how did she get free?’ Rhona said.

‘Some ties have ragged edges, and look’ – Chrissy pointed to one of the metal uprights where traces of the plastic had lodged – ‘it looks as though she may have managed to rub herself free and made her way outside?’

Rhona ran her eyes over the room again. To one side of the bed lay a pair of high heels which looked like the victim’s shoe size. ‘Did you find any underwear?’ She had decided not to remove the outer clothes before the autopsy, for fear of disturbing evidence on the charred body.

‘A black lacy thong,’ McNab said. ‘It’s been bagged.’

The picture being painted by everything they’d already discovered in the room wasn’t lost on anyone, least of all Rhona.

‘I’ll get a team in here and see what else we can find,’ Chrissy said, ‘while you finish up in the tent.’