I fling open my door at exactly the same time as the guy in the Lexus exits his car.

‘I’m sorry,’ I say, barely concentrating on him. ‘I’ll be back in a minute!’ I take off down the street after the couple.

‘Hey! Where d’you think you’re going?!’ A hand grips the shoulder of my coat and yanks me backwards.

I half turn and try in vain to shake him off. The man’s face is red and he’s wearing a look of outrage.

‘Let go of me!’ I cry. ‘I have to… I said I’ll be back in a second! I just… I saw someone who I think might be my sister—’

‘You’re not going anywhere until I’ve got your details! You can’t just run off from the scene of an accident.’ The man is tall and broad shouldered, well groomed, wearing a suit. ‘This car is brand new! How the hell did you get a licence? You weren’t even looking at the road. I saw you in my mirror, staring over there at the pavement like an idiot.’

‘Honestly, I’m sorry,’ I repeat, shaking myself free of his grip and taking a step away from him in the direction of where the couple disappeared. ‘Look, please just let me quickly go and see if that’s my sister. She’s literally just gone down that road. Please. Would you mind?’

‘Would I mind?’ he says incredulously. ‘Yes, I would mind. You need to give me your details.’

‘I’ll only be a minute and then I’ll come straight back, I promise.’ If the man didn’t look like he’d tackle me to the ground, I’d run after them and deal with the consequences of the crash later.

‘If you do a runner, I’m calling the police. I just don’t bloody believe this. I wasn’t even supposed to come through Shaftesbury, but there was flooding, so the satnav brought me this way. This is all I need!’

I feel like crying, but I can’t add a police enquiry to everything else going wrong in my life. ‘I wasn’t going to run off, I just need to… oh never mind. Can we do this quickly then?’ I resign myself to the fact that I’m going to have to stay here and deal with this.

He rolls his eyes and mutters under his breath, shepherding me back down the street.

Before moving our cars to the side of the road, he takes photos of both vehicles from all angles. Then we spend a good few minutes exchanging numbers and insurance details. And all the while I’m cursing myself for not getting away from him in time to see if that really was my sister.