A Perfect Spy, by John Le Carré. Published by Knopf in 1986, now available in a Penguin reprint.
I read this book when it first came out and thought it a masterpiece. I re-read it recently with some trepidation, fearing I would be embarrassed by my earlier enthusiasm. I needn’t have worried: it remains a brilliant novel by any standards, and the character of Rick Pym, the protagonist’s father, is unforgettable.