But Pip knew she couldn’t do that. The woman, Robbie’s mother, had taken the time to put her anger and pain into a letter and the least Pip could do was to read it, absorb it, take some of it on to her own shoulders. She braced herself for what was to come and read on.

I’ve thought about what happened and how Robbie died and how you came out of it without a scratch on you. And to start with I was so angry. I really hated you. It wasn’t fair that my beautiful boy had to die when you’d just walked away scot-free.

But then I thought that you didn’t walk away, did you? Not really.

My lovely Robbie – he’s gone forever. He’s not coming back. I’ll never see him play football for Arsenal (did you know he was a Gunners fan? He had his shirt on that day. He never took it off unless I made him). I’ll never see him get a job, get married, have kids of his own. And that hurts – God, that hurts so much. But he’s gone. He doesn’t know any of it.

But you. You have to live. His life was gone in a second but yours goes on and on. You have to think about what happened every day. I guess it’s always in your head, like it is in mine, and it never goes away no matter what.

The difference between you and me, though, is that Robbie was my boy. I’m going to grieve for him forever. But you. You shouldn’t have to spend the rest of your life suffering. That really isn’t fair.

Pip had been bracing herself for the impact of the mother’s words to hit her between her eyes and knock her sideways, but now she stopped in her tracks. What exactly was the letter trying to say? She went back and reread the last two sentences. This was no condemnation. The mother wasn’t damning her for all eternity, as Pip had assumed she would. Cautiously now, she let her eyes trace the rest of the letter.

My baby is dead and he’s never coming back. But your life shouldn’t be over too.

I know what happened was an accident. Robbie just ran out. He was always doing it. I told him over and over, but you know what boys are like. He thought he was invincible and that I was stupid, fussing all the time. When the police came to my door, I knew exactly what had happened. I’d almost been waiting for it.