Hannah turned. The counsellor was about the same age as her mum, purple hair chopped short, black frilly top, leggings, Doc boots, biker jacket on the back of her chair. Hannah wondered how she came to work for Edinburgh Uni, talking students through their crises. Most of them would be stressing over exams, depressed about breaking up with a boyfriend or girlfriend, confused about their sexuality. Hannah could trump that.

‘You mean apart from the fact my dad killed my friend, who was carrying his baby, then tried to kill my mum and gran?’ she said.

Rita gave her a look like a kicked puppy.

‘I’m sorry,’ Hannah said.

Rita held out her hands. ‘It’s what I’m here for. You’ve been through a lot. Anger is reasonable.’

Hannah shook her head. ‘I’m not angry, that’s the thing, I’m just tired. So fucking tired.’

Rita nodded and crossed her legs. ‘Again, totally reasonable. I’d be tired. Anyone would be tired in your situation.’

Hannah’s girlfriend, Indy, had floated the idea of therapy or counselling a month after everything happened with Craig, when it was clear Hannah was struggling. Dorothy suggested a private shrink but Hannah refused. They cost a ton of money, and Hannah believed that talking to one person about your shit was the same as talking to anyone about it. Would a psychiatrist wave a magic wand and make it all go away? So here she was talking to an ageing rock chick who no doubt had a bunch of her own unresolved shit to deal with.

Hannah had never told Rita they had a view of the crime scene from her office window. Normally Hannah liked talking, she’d grown up connected to the world in a way Rita’s generation could never grasp. But she didn’t want to talk about this. What difference did it make? Mel was still dead, her dad was in prison, and everyone still carried the scars.

‘Have you heard of the many-worlds interpretation?’ she said.

Rita tilted her head. ‘No.’

‘But you know about Schrödinger’s cat?’

Rita frowned. ‘Something about a cat in a box that’s alive and dead at the same time.’

Hannah smiled. ‘Kind of. It’s quantum mechanics. On a subatomic level, a particle is in an indeterminate state until it’s observed. So what if you scale that up? Put a cat in a box with a flask of poison and a radioactive source. If the source decays, a quantum event, the flask breaks and the cat is poisoned. But until you open the box you don’t know whether the source has decayed, so the cat is both dead and alive.’

‘OK.’ Rita dragged the word out.

‘It’s a paradox, but there’s a way out of it.’

Rita waved a hand.