The blow sends the woman flying backwards in an almost cartoonish fashion. She lands flat on her back, a stunned expression on her face as her skull smacks the tarmac hard, blood spraying out of her mouth. Is that a tooth, flying off in the opposite direction?

Catherine has jumped into the van and Graeme has driven out of the car park before she’s even had time to get her seatbelt on.

Graeme drives steadily, nothing flashy, nothing to draw attention to them. Even if there is CCTV in the car park, there is nothing to identify the van. His hands have stopped shaking. A huge beam spreads across his face, even though they aren’t high and dry just yet.

‘We did it!’

‘I did it, you mean.’

‘Yeah, babes, I know.’

Conciliatory as always, Graeme does know. But he also knows that it has been all these months and years of preparation on his part that has got them to this stage. Making sure Catherine took her meds, back when she was still in Rampton; urging her not to blow her top whenever someone wound her up. Both of them knowing how crucial her good behaviour was.

Catherine has behaved herself for the last three years. It’s a record.

But then, when Catherine really, really wants something, she’ll do anything to get it. Graeme likes to think that Catherine’s good behaviour was due to his influence – and perhaps too the fact that he persuaded the board to let him be Catherine’s advocate. All the dozens of Care Plan Approach meetings he’s attended on her behalf, feeling like a proper responsible citizen.

The joy they both felt when it was deemed that Catherine’s condition was finally stable enough for her to be moved from high-security Rampton into this medium-security place in Surrey … The plan was working, he thought. For the first time in his life, Graeme had a purpose, a mission. Not to mention all the other planning he had to do, to set everything up for Catherine. Convincing the CPA board to consider transferring her hadn’t been easy, but they’d done it. Graeme had insisted it was because he’d got a new job, as a gardener, and he wouldn’t be able to continue driving up to Nottinghamshire to visit Catherine. They wanted to be closer to each other; that was fair enough, wasn’t it? They were a couple.

And the board bought it, not having a clue why Graeme had got a gardening job at that particular venue.