Although it seemed likely that the murders were linked, the police had to explore the idea that it could be a coincidence. It was their job to look at things from every angle, no matter how unlikely certain scenarios might seem. It was time-consuming, but their responsibility to follow the ABC of policing: assume nothing, believe no one, challenge everything. The problem was that the team had applied this mantra to the investigation, but they were still struggling to come up with a solid motive, let alone a suspect.

Barrett watched as a group of schoolkids kicked a ball about on the green during their lunch break. He wondered how anyone could contemplate playing football in that heat and never failed to be impressed by the resilience of young people. That thought led him to consider Dean Cox: what would happen to him? He was pleased that the boy was with his grandmother, or at least he had been until she’d started calling the station and ranting like a lunatic, but Barrett knew as well as anyone that family relationships could be complicated. It was one of the reasons he avoided his own.

‘Sir, sir!’ A shout came from the other side of the incident room and Barrett spun around to see DS Singh hopping up and down next to his desk. ‘I’ve managed to access the iCloud account of Janet Cox. You need to come and see this.’

Amy, who had been sitting by Johnny’s bedside, had called the nurse when she noticed he was turning blue and the machines he was hooked up to had started beeping. She was quickly ushered into the relatives’ room while the doctor rushed to examine him.

Amy had been waiting five minutes for some news when a troubled looking nurse appeared in the doorway of the relatives’ room.

‘Amy, I’m afraid I’ve got some bad news.’ Her face was pale and her hands were clenched together. ‘There has been a complication. I’m afraid your husband’s lung has collapsed; we are doing everything we can and are preparing him for surgery.’

‘What does it mean?’ Her heart pumped furiously in her chest and she could feel her pulse throbbing in her temples.

‘The doctors will do everything they can. He’s in safe hands. The aim of the surgery is to remove the damaged tissue that has caused the pneumothorax.’

Amy stared blankly.

‘Collapsed lung,’ the nurse corrected herself.

‘Are there risks with the surgery?’

‘Every surgery carries a minor risk,’ she answered steadily.

‘Can I see him before he goes in?’ Amy was shaking and Maggie had come to her side and slipped her arm around her friend’s shoulder. Marion sat, frozen to the spot, shocked and terrified in equal measures.

‘The anaesthetist is on his way. You’ll have a minute or two but please, keep it brief.’