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 Cian did want to know. And he had five months left. And he spent them in cafés, with her.

And the one thing in that letter I have never shown anybody, including Lena.

Page three. Four lines, on their own, halfway down.

***Mum, I’m not doing this because I’ve forgiven him. I haven’t. He gave me this and he gave her nothing and I’d like to have said that to his face.***

***I’m doing it because she’s the only bit of him that isn’t finished.***

My son was nineteen and dying of something his father put in him, and he worked out — on his own, in a hospital bed — the difference between forgiving a man and refusing to waste what was left of him.

I have read those four lines more than the rest of the letter put together.

I am fifty-one and I could not have written them.