Wandering around Greenwich Market with Caroline, I spotted this book, and remembered the controversy surrounding this book from my childhood. At the time I didn't really understand it. Even now, it doesn't really make sense, seeing as it was banned in the UK and freely available in the rest of the world.
Anyway, I found it fascinating. While it avoids going into too much technical detail, the science involved in counterespionage in the mid-twentieth-century is rather interesting. The insights into the Cold War, the petty politics, the ruthlessness of the Russians and the amateurish old school ties ways of MI5 fit together marvellously.
It makes a perfect partner to le Carré stories, allowing you to see where truth and fiction merge. In fact, it's rather easier to read, and some of the stories are as good as fiction, although it must be said that it's not really a patch on it as literature goes (no surprises there). Oddly, while le Carré's stories leave you guessing as you read with a decent resolution, this book obscures nothing as you read it, but leaves you with the same unresolved mysteries Peter Wright was left with at his retirement. Was there an uncaught high-level spy in MI5? Perhaps they've found out in the last 30 years, but they certainly won't tell us. Unless another retiree becomes disatisfied with his pension....