The Inverted World is a cold book.
Most of Priest's books are told in a stiff and remote mode, which frequently suits the alienated subject matter. It's not the case here.
1 - The sterile environment depicted is reflected in the unemotional natures of the characters and of their relationships with one another: Helwood vs his wife Victoria and Helwood vs his father;
2 - The dialog is very stilted and stiff; it barely pretends to achieve more than information exchange. And as a result, it is difficult to become involved in the characters' lives or to care about their feelings;
3 - The leitmotiv of the book is abandoned three-quarters of the way through;
4 - It lacks an explanation on how the characters moved from this world to the Inverted World;
5 - The books wrap-up at the end, ie, "The Explanation", leaves a lot to be desired. There're lots of questions unanswered. Intentional?
1 - It has a mind-boggling idea that is at the very heart of the novel.
Compared to his later books I think it lacks the subtlety and ambiguity expected from him.
It's well worth the read simply for its basic concept (3 stars for that).