‘I think it’s a completely reasonable question actually,’ I go on, my heart beating quickly. ‘You had my daughter earlier. And now, here you are again.’

He turns off his engine, and I brace myself in case he gets out of the car.

‘I think you mean: I found your daughter earlier and returned her afteryoulost her. Which you didn’t seem all that bothered about, actually.’

‘Of course I was bothered,’ I snap. ‘And I said thank you, didn’t I?’

‘You didn’t say it like you meant it.’

‘Well, I meant it. Thank you. Now, can you please answer my question. Why are you following us?’ My words are clipped and confident but inside I am trembling. If this Shayne guy turns out to be a psychopathic serial killer, I’m not sure I could save a child and an old man at the same time.

Shayne leans forward to stare past me at the bench. ‘Hello, Grandad,’ he says.

Malcolm huffs. ‘Spying on me again, are you?’

‘It’s not spying.’ Shayne rolls his eyes. ‘It’s just a tracker on your phone so I know where to find you.’

‘Techy nonsense.’ Malcolm waves his hand dismissively.

‘Well, building apps is my job.’

‘Damn phones,’ Malcolm goes on, patting his pocket, where I guess he keeps his phone.

‘I wouldn’t be able to find you without it. And when you’re not where you’re supposed to be when I come to pick you up, I’m very glad you have it.’

So, Shayne picks Malcolm up every day at the hospital, I decide, joining the dots in my head. I’m glad he has someone come to fetch him. But it still doesn’t explain why he’s going there every day.

‘Your grandfather,’ I say, staring at Shayne as I look for a resemblance.

‘Yes. Hi. I’m Shayne Fairbanks,’ Shayne says, opening the door of the car to step out.

I’m no longer nervous, but I am embarrassed. I wish I hadn’t been so noticeably on guard just now. I notice Shayne and Malcolm’s eyes are similar, and their chins. Shayne certainly has more hair; a floppy mop of brown curls bobs on his head, ruffled by the wind.

‘You two know each other?’ Malcolm says, drawing an invisible line in the air to join Shayne to me.

‘Not exactly,’ Shayne says. ‘We met briefly. At the hospital. I was looking for you actually. You weren’t answering your phone and I was worried.’

He slides his phone out of his coat pocket and turns his screen towards Malcolm to share that he has made seventeen attempts to call his grandfather today, all of which have gone unanswered.

‘That thing,’ Malcolm grunts, scrunching his face to read the screen. ‘Can’t get a minute’s peace any more. Everyone going around with mobile phones in their pockets. In my day a man could go for a walk to clear his head and no one pestered him until he came home.’

‘You’ve been gone since lunchtime,’ Shayne says. ‘And you forgot your hat.’

He pulls a colourful hat from his other pocket. It’s a perfect hand-knitted match for Malcolm’s scarf and I find myself wondering if Shayne has a loving grandmother at home who is wonderful with a pair of knitting needles.

Malcolm shakes his head.

‘But it’s cold, Grandad…’ Shayne trails off and I pick up a sense of something between them. An unresolved argument or something.

‘It really is very cold,’ I tell Malcolm.

‘Gosh, really, and here I was hoping to do some sunbathing this evening.’ Malcolm chuckles, amusing himself much more than either Shayne or me.

‘Okay, suit yourself, but will you at least get in the car? I have the heated seat on, so you should warm up soon.’

‘Who says I’m cold?’ Malcolm says.

‘I’m cold,’ Ellie joins in, her teeth chattering like a prop in a play.