Iris found the letter inside a library book on the third shelf from the bottom.
It was handwritten, dated four years ago, addressed to "Whoever Finds This."
It said: I am eleven. I am having a terrible week. I don't know who to tell, so I'm telling a book. If you find this: I hope your week is better than mine. Write back if you want. Leave the letter in the book and put it back on the shelf.
There was a first name at the bottom. No address.
Iris thought about it for two days. Then she wrote back.
She said: I'm eleven too. My week is fine but I'm sorry yours was bad. Here is something that helped me once: my mum says bad weeks end. Even when it doesn't feel like they will.
She tucked it in the book and returned it.
Three weeks later, she checked. The letter was there — with a reply.
They wrote back and forth for a year, leaving letters in a book on the third shelf from the bottom. About school, about families, about what they wanted to do when they grew up.
They never used last names. They never arranged to meet.
But Iris always smiled when she walked past that shelf.
Some friendships don't need faces. They just need honesty and a book left in the right place.