Espionage raised to the level of literature: a genre invented by Graham Greene. The language of this novel is so exquisite. Some of the sentences will melt you with relish. The vulnerability of someone who is in love is a topic often revisited by Mr. Greene. More than the taut thrilling sequences, more than the page-turning plot, when reading Mr. Greene, we cannot help but be marooned in the cavernous beauty of the language.