First of all, I have to admit that I had some doubts with my rating of the book. From the one hand, in its genre it is a very good example of easy-reding, it might be mentioned that "Skios" does not pretend to be a serious book with strong system of images, which needs careful analysis. Moreover, when I discovered that the author, Michael Frayn, is 80 years old I was almost shocked, because the book looks very contemporary, it has very nice language, without difficult constructions. So, it is not masterpiece for rating 5, but a very strong 4. From the other hand, even for rating 4 the book is not very touchable, from my point of view. Oliver Fox has not enough charm, the women are a little bit silly, the actions of Wilfred are not understandable. The majority of heroes are "stamps" (unlucky, absent-minded scientist, young girl etc) I was not quite sure if this book was worthy of even 4 (in parallel with another books og genre "easy-reading").
Nevertheless, I want to emphasize the moments which I liked in "Skios". Firstly, the plot is quite greeping, even though it is very old (I mean the idea of "missing identities"), it is the advantage of the book. To my mind, this thought is the deepest of the book: the question, of who we are, and who we want to be is still unanswered and everyone has his own answer. Secondly, some episodes (I would not spoil) are really laughable. Finally, I practically always appreciate the idea of "invented geographical object", like the island "Skios", because it is a good metaphor.
In conclusion, I may recommend this book for the leisure time, when you do not feel enthusiastic to read a serious literary work. It is indeed well written, and also out of respect the experience of the author my rating is 4.