I can imagine that receiving a letter from me might seem strange after all these years. However, I write to you as Valentin's professor with his best interests in mind.
Our old friendship has made me take an interest in Valentin's welfare and a few months ago I noticed how he obviously wasn't getting enough sleep. I made sure he received some sleeping potion and also took it upon myself to have talks with him to ascertain his problem.
The problem is quite simple - he misses his father greatly and this has evolved into a full blown depression. As his professor I wish to help him and I find that the best step in that direction would be to allow him to see his father.
I understand that you and he are divorced, however I hope that you can see beyond your differences with Valentin's health in mind. It would mean a great deal to him.
Yours in fond memories, Adrian Pucey, Professor of Ancient runes, Hogwarts school