My twin sister vanished in her sunflower sweater on our 16th birthday — 40 years later, my granddaughter came home wearing it and said, "Our school cleaning lady gave it to me."

The envelope was thin.

One page, maybe two.

I sat in the car park of the nursing home with the engine off and the heater still ticking as it cooled, and I opened it.

Laura's handwriting was nothing like I expected.

I had held onto the image of her looping teenage letters for forty years.

What was on the page was smaller, more careful.

The handwriting of someone who had learned to take up less space.

*Dear Ellen,*

*If you're reading this, Rosa kept her promise.

I always knew she would.

She's the best thing I ever did.*

*I've started this letter so many times.

I've thrown away more versions than I can count.

I'm going to try to just say it plainly, because I don't have much time left and I don't want to waste any of it on the right words.*

*I didn't run away.

I want you to know that first.

I know that's what everyone must have thought.

I need you to know it wasn't true.*

*Dad found my notebook.

He came to my room that night while you were all at the table.

I heard him on the stairs and I knew.

I went down to the garden and he was already waiting.*

*He wasn't angry.

That was the worst part.

He was very calm.

He told me what would happen if I stayed.

He told me what he would say to the police.

He had my handwriting on some papers — I still don't know how he got it, whether he copied it or whether Marsh did it.

He showed me.

He said it would be easy to believe.

A teenage girl, access to the house, resentful.

He made it sound very reasonable.*

*I believed him.

I was sixteen and he was my father and I believed him.*

*I kissed Mom.

I took the frosting.

I said save me a slice because I thought if I said something ordinary, something normal, it would feel less like goodbye.

I thought maybe it wasn't really goodbye.

I thought maybe I would find a way back.*

*I never found the way back.*

*I want to tell you about my life, but I also don't want this letter to be too long, because I know you'll cry and I don't want you to cry for too long.

I was all right, Ellen.

I want you to know that.

I had a life.

I had Rosa.

I had a small apartment with a lemon tree outside the window and a neighbor who taught me to make soup and a job I was good at and years that were hard and years that were better.*

*I thought about you every birthday.

Every single one.*

*I thought about Mom.

I thought about calling so many times.

I was afraid.

I was ashamed, even though I know now I had nothing to be ashamed of.

By the time I understood that, so much time had passed that I didn't know how to cross it.*

*I'm sorry I didn't find a way.

I'm sorry I turned around at the airport.

I'm sorry Mom d*ed not knowing.

That is the thing I carry the most.*

*Tell Rosa she did everything right.