First thing the following morning, the team gathered in the incident room to discuss the latest turn of events. Doris Adams had been pronounced dead at the scene and Alex had already heard from fire-scene investigators that the fire had been started from inside the house. The information triggered an immediate surge of murmurs among her colleagues.

‘Signs of a break-in?’ someone asked.

Alex nodded. ‘Back door had been forced. Fire was started with petrol – a brand test is being carried out; the results should be with us by tomorrow.’

‘This is showing all the same hallmarks as the fire at the hospital then?’ DC Jake Sullivan said.

‘So far, yes. The test on the petrol will give us a stronger link.’

‘Was she beaten before the fire was started?’ Dan asked.

Alex nodded. She had already spoken with the pathologist and had gleaned enough information to know they were looking at yet another brutal attack. ‘We’ll have more details when the post-mortem report comes back.’

A moment of silence fell over the team. Each attack had been vicious, but this latest seemed particularly callous. Doris Adams had been a blameless victim; an elderly woman murdered in her own home for no apparent reason. Whoever was responsible for her death, and that of Gary Peters, was guilty of the worst kind of crime. This was murder for murder’s sake, and there was little doubt in Alex’s mind that the same perpetrator was responsible.

She turned to the evidence board. ‘SOCOs have lifted a print from the front door frame of Doris’s house, although the fire was started at the back. It’s not come up as a match with any on the database. We have Gavin Jones’s fingerprints on the petrol can located near the attack on Corey Davies, but as we know, his alibi for Saturday evening is solid. The Hassan brothers,’ she pointed in turn to photographs of Syed and Jameel, ‘keep cropping up.’ She pressed her fingertips to her left temple and stepped away from the board. ‘Syed Hassan has previous cautions, but his prints aren’t a match either. By all accounts he got himself involved with a few gangs when the family lived in Cardiff. Keeping their son on the straight and narrow was a motivation in their move to the valleys.’

‘That was a success then,’ Jake quipped.

Alex’s top lip curled. ‘The more this case escalates, the more I think we should be separating the fire at the Hassan shop from the rest of the investigation.’

‘How come?’ asked Chloe.

‘The fire at the hospital holds several similarities to the arson at Doris Adams’s house last night. Vulnerable victims, as we’ve already discussed, and both targeted in their homes.’ Alex made inverted commas gestures at the last word. ‘It seems Gary Peters may have been using the hospital as a base for some time, which would suggest he felt safe there, or at the very least safer than anywhere else. Gary and Doris were both attacked in places they might have least expected it – places where they would have been caught off guard. There was no victim at the shop fire – not in the physical sense, at least. It was targeted at night, at a time when whoever was responsible would have known there was no one inside.’

She paused, her attention still focused on the images of the Hassan brothers. ‘Do we know anything about the Hassans’ finances?’

Chloe shook her head. ‘You think Syed or Jameel might have started the shop fire?’

‘We know they’ve both got form, particularly Syed. Gavin Jones has admitted to fighting with them on Thursday evening. Perhaps one of them hoped to frame him.’

‘But why destroy their own family’s shop?’ asked Jake.

‘That’s why I’m questioning their finances. If they have money problems, they might have seen this as a way to kill two birds with one stone. Or with one petrol-soaked rag, anyway.’

‘And you still think the attack on Corey Davies might have been a copycat?’

‘It doesn’t follow the pattern. That incident was more frenzied. The perpetrator was clumsy. It doesn’t match the other attacks in any way, other than the use of petrol. Dan, did you manage to get anywhere with the Xbox username Faadi gave to Chloe?’

Dan shook his head. ‘The name’s no longer registered. Whoever Bottleman was, he knew exactly what he was doing – there’s no way of tracking the username to an IP address now the account has been deactivated.’

‘So if the account was used to target Corey on Saturday night and find out where he was, this person could do the same thing again to trace another victim?’

Dan nodded. ‘Unfortunately, yes. If the account exists, the user can be tracked. Once it’s no longer up and running, that’s it.’

‘I might have found something else.’

All eyes turned to Chloe, who stood and went to the laptop at the desk near the evidence board. Alex stepped aside, allowing her to access the internet search engine. The web page was projected onto the screen behind her so that the rest of the team could see what she was viewing. She typed the word ‘bottleman’ into the search bar, then pointed to the fifth result that was thrown up. ‘Catfish and the Bottlemen. They’re a band from north Wales.’ She returned to the search bar and extended her request with the words ‘Kathleen lyrics’. ‘Look,’ she said, pointing to the screen behind her. Her fingertip scanned the page of lyrics, stopping at the start of the second verse. ‘Impractical. Death.’

‘The 999 call that was made on the night of the fire.’

Chloe gave Alex a nod. ‘Listen.’ She searched for YouTube and found the track titled ‘Kathleen’. After skipping the first minute of the music video, the short sound clip that had been enhanced from the 999 call could be heard. ‘It’s definitely the same song.’

Alex shot her a smile; the first she had given anyone in days. ‘Well done, Chloe.’

‘You know what this means, though,’ Dan said. ‘Whoever made that call on Thursday evening may be the same person who played FIFA against Corey and Faadi on Saturday.’

‘So the attack on Corey might be linked after all?’ asked Jake.

Alex nodded. ‘Seems possible. But there’s still something not right about it. The incidents were so different. Maybe we’re looking for more than one person.’

‘So what do we do now?’ Chloe asked.

‘Let’s step up the pressure on the Hassan brothers, for starters. Dan, we need some background checks on their finances – let’s find out how the shop’s been doing recently. Anyone we speak with now, I want the ringtone on their phone checked out. I don’t care how you get it done – just think of any excuse, okay? Chloe … great job.’

Chloe gave her a nod to acknowledge the praise. Under the circumstances, Alex knew it was the best she could hope for.