They retrieved anti-contamination paraphernalia from their respective vehicles and suited up before approaching the building. The uniformed officer renewed his stance as they came close.

Hawkins produced her warrant card. ‘DCI Hawkins and DS Sharpe.’

‘Constable Jones.’ The uniform smiled sarcastically.

She moved to pass him, but the officer blocked her path. ‘Sorry, ma’am. Head SOC says nobody in or out till he’s ready.’

She stopped, feeling the frown descend. ‘Let me explain how this works, Constable. The point of forensic investigation is to aid the collection of evidence to support an accurate conviction. But the whole operation is futile without a suspect, and no amount of tweezer work or micro-examination is going to secure one of those. For that, you need detectives like me and my sergeant, who just happen to have half a dozen people under arrest; all of whom walk at eight o’clock this evening, unless we link them to these murders. They might be completely innocent, of course, but we won’t know unless we get a decent look at what’s inside this flat. So, if you’re posted on the door of a crime scene, and someone who outranks everybody else on site turns up and wants to go in, it’s probably a good idea to let them.’ She cocked her head. ‘Don’t you think?’

Jones muttered, his eyes dropping, ‘Sorry, ma’am. Go on.’

‘Super.’ Hawkins waited for him to step aside and ducked past the crime scene tape, donning overshoes, gloves and a mask as she entered. Aaron followed her into a dingy hallway with fading blue and green wallpaper. The air was stale, but otherwise the place smelled habitable, and the two bedrooms visible from this end of the hall still had bedsteads and mattresses. Yet her attention was drawn to the far end of the corridor, where an open door led through to the living room. Winter sunlight blazed through the net curtains, almost silhouetting the figures moving busily back and forth across the room.

She set off, peering carefully into the cramped bathroom and kitchen, positioned opposite one another halfway down the corridor. Nothing amiss at a glance.

As she backed out of the bathroom, Hawkins trod on the corner of her left overshoe and stumbled. She gasped as her steadying hand jarred against the rough door frame, the sharp tear of a splinter driving itself under her skin.

‘Steady.’ Aaron hovered, arms spread as if he were ready to catch her, but not actually helping.

She righted herself, aware that his hesitation was likely to be a result of her own prickly demeanour, but still too wound up to care.

The sergeant lingered as she propped her back against the wall and began wrenching her overshoe straight, hoping that perhaps this new crime scene would at last start moving them towards a resolution. Considering the events of the last twenty-four hours, they were due some luck.