Ellie was going to speak, and then stopped. It wasn’t impossible. Things went on behind closed doors all the time – abuse, addiction, relationships gone horribly sour and lethally toxic. Sometimes there were signs, clear in retrospect but meaningless or merely odd at the time. And sometimes the first you knew of it was when it was over. She remembered one of the worst cases she’d handled in Manchester. A family only a few streets away from her; she’d bumped into the dad in the corner shop a few times, waved to the mother as she did the school run with the kids. The dad had been a pleasant enough bloke – funny, friendly. A bank manager. And then one day Ellie had been sent to take a look, because neither parent had been in work for a week, nor the kids been seen at school.

It’d been summer. The car in the drive. Curtains drawn. No-one answering the door. A judgement call; Ellie had busted the patio window and gone in.

The garden had been overgrown with buddleia; that’d been a sign right there, in retrospect. It’d been left to grow wild for over a month. Buddleia was a nightmare if you let it get hold, and they had. Until she’d broken that window, all Ellie could smell was its sweet, honeyish scent; whenever she smelt that now, it made her sick. The odour that had spilled out of the shattered window had obliterated it.

The husband had had a gambling addiction, and been embezzling to cover it. Shifting money between accounts to buy himself time, needing a bigger and bigger win each time to try and fill the hole. The house had been heavily remortgaged, without the wife’s knowledge. But it had all been about to come crashing down around him. Up to that point Ellie could have pitied him, but not what he did next.

There’d been no evidence of a struggle; they found cups of unfinished cocoa laced with GHB. The wife and children had been strangled: the husband had lain down beside them, then cut his throat with a Stanley knife.

That had been in a cul-de-sac, part of a row of identical new-build houses. Clean, pristine and tidy, with only the drawn curtains, that morning, to set them apart from the rest. Ellie had never been able to look at houses like that since, not without wondering what might be going on inside. Made her nineteenth-century terrace here in Barsall that much more appealing.

Oh, yes. Anything could go on behind closed doors. Barrowman Farm was another case in point.

“What about the Harpers?” said Milly. Great minds clearly thought alike. “You said yourself they’ve cranked up the mental.”

Ellie had to laugh. “Cranked up the mental, doctor?”

Milly started laughing too. “About right though, innit?”