page and screen

I enjoyed the TV show, The Man in the High Castle, so much that I got the book by Philip K Dick. It's a good example of the principle that, to faithfully adapt a book for the screen, you have to change the story in fundamental ways. 

The basic idea is the same. The axis, not the allies, won the second world war, so America is governed by the Reich and the Japanese. There is a subversive text or set of texts that show a world where the allies won. In the TV show, the subversive texts are films, but in the book, it's a book. 

It makes a lot of sense when you think about it. In a TV series - a text on a screen - the subversive text is a film - a text on a screen - but in the book, it's a book. In a funny way, it's not even a change. It's a direct adaptation. It's faithful to the spirit of the book, not the letter of the book.