Our worst enemies here are not the ignorant and simple, however cruel; our worst enemies are the intelligent and corrupt.
For some reason, I had it in my head that The Human Factor was one of Greene's quartet of Catholic novels. The edition I read didn't have a summary on the back, so I was surprised when I started it and found that it was a spy story, a genre Greene touched on every so often throughout his long and varied career.
The Human Factor is the story of Maurice Castle, an MI5 agent married to a black South African woman. When information leaks are discovered in Castle's department, suspicion falls on his coworker, a young man named Arthur Davis. The bureau arranges Arthur's death, although they have no definite proof of his double-agency. It turns out that Castle is the double agent, turned during his time in Africa because of a desire to help his wife's people escape the scourge of apartheid.
The Human Factor's MI5 department is the anti-Bond. Castle and his coworkers feel about their jobs the same way a salesman or a hatmaker might feel about theirs: it's money and it keeps the lights on. No one, not even the high ranking officials who eventually seal Castle's fate, see their job as a great national responsibility. They all function as their own tiny piece of the whole, comparing their positions to “boxes” which they need never leave and no one else need enter.
Like most of Greene's books, the plot is of secondary importance to the themes he chooses to examine. However, unlike The End of the Affair, there's still much enjoyment to be gleaned from the plot. Greene does an excellent job of presenting Castle, a man ill-suited for his chosen lifestyle as informant. There is a palpable air of paranoia during even the most mundane domestic moments of Castle's life. A less capable author might have spelled out too explicitly, but which Greene lets linger and grow until the inevitable explosion.
The novel is also an examination of loyalty and integrity, and it never points a finger at Castle for his traitorous actions. The villains of the piece, such as they are, are simply doing their jobs, plugging the leaks the best way they know how. It is Castle, with his willingness to betray his natural-born country for the country of his wife, who seems most heroic, even while his character lacks most of the characteristics we've come to associate with that title.
While I wouldn't say The Human Factor is the best book I've read of Greene's, it is one of the best spy novels I've read, and there's a lot going on underneath. It was entertaining (Greene himself considered it an “entertainment”, not a novel) and worth reading if you enjoy Greene's other books or spy stories.
Fake edit: While doign some reasearch, I learned that Greene actually worked for MI5 for a while, and part of this book is based on his own experiences, although, I'd speculate, a very small part. Still, cool.