Home Fire by Kamila Shamsie Bloomsbury, 2017, 260 pages, $24.99 __________________________ For years now Kamila Shamsie, Pakistani-born, long resident in London, has been one of those novelists you have to watch. Books like Burnt Shadows and A God in Every Stone succeeded in inhabiting contrasting worlds, British and subcontinental, with absolute credibility. Shamsie has always been a writer who could tell a story and capture a voice and show the ways in which worlds that shared so much could seem to converge, then fall apart. Now she has written a book which should rivet the attention of the world. Home…