This book is a masterpiece – and not the only masterpiece that John le Carré ever wrote. Read it now, and then think about all the other books about British spies you’ve ever read. Le Carré invented an entirely new genre of fiction and in the character of George Smiley, one of the great characters in English literature. I will shortly be reading the other two books that are, together with this, considered to be the “Smiley vs Karla” trilogy. I cannot wait; he is that good.