Hope you don't mind I copied and translated your post into English.
. Apologies if a.i. misrepresented any of your words.
Incredibly exciting novel! Perhaps, of course, it's my favorite of those I've read, and I've only read 8. It seems to me that it was safe to make a separate film based on "The Edge of the Mirror" - this is a very high-quality story about what happened before the events in "Mirror Reflection". It was very nice that Sam finally recovered his memories and was able to chat with Tom and Donne before disappearing from their lives forever.
The only thing I didn't like about this novel was the character David Allen. I don't understand why Carol Davis introduced a complete stranger to the novel, but she didn't write a word about Tina! She also made sure that this David Allen had to travel in time instead of Sam. Why? Strange... But, in general, it doesn't spoil this brilliant novel!