Before my 19-year-old son di3d, he donated his heart to an 18-year-old girl — after the transplant, her mother handed me a letter from my son that began, “Mom, there’s something you need to know about her.”

And she let them meet anyway.

And she never once contacted me. Not to accuse me, not to apologise, not to ask me for anything. For eighteen years, and then through five months of cafés, and then through a transplant.

The first time that woman ever spoke to me was at my son’s funeral, to put a letter in my hand.

What I had to take.

I knew.

Not her name. Not a daughter. But I knew there had been somebody, in 2006.

There was a phone. A second one, in the glovebox, that he said was for work. There was a weekend in the November of 2006 that was a conference and was not. There was a woman’s voice that said sorry, wrong number in a way that was not right.

And I was thirty-one, with a baby, in a flat with damp in the back bedroom, and my husband earned all the money.