“I’m taking care of it,” I told her.

“I need you to trust me and stay safe.

That’s your only job.

Can you do that for me?” She nodded, and I watched her walk through the school gates, and I did not know it would be the last easy moment of that day.

I have thought often about how to talk to a child about a horror, because that morning in the car I had to do it with no preparation at all.

Every instinct of parenthood is to protect a child from exactly this kind of knowledge — to keep the world soft and safe, to let them believe the adults who love them are all trustworthy.