Arthur Koestler's "Darkness at Noon", his magnum opus, is more than just a book. It is not a novel, nor is it an essay; it is a memory and an experience, a warning and a vision. It takes the reader into a nightmare world that is nevertheless real, an alternative history that is more history than alternative, and if he has a sensitivity to questions of history and politics, it is sure to be imprinted on his mind forever. In summary, it's one of the most powerful political books of the 20th Century.
The theme of the book is the experience of Stalinism, in particular the Stalinist Great Purges and the show trials during the late 1930s. Arthur Koestler himself was a Party socialist for much of his life, and only left the Soviet Union in 1938. Having known many of the Old Bolsheviks personally, he saw the state of the revolution taken over by Stalin and his henchmen, and witnessed the slow (and sometimes fast) destruction of the revolutionary old guard.
It's the experiences of this infamous Great Terror of communism, seen from the eyes of a communist, that form the basic of this book. The plot is rather limited in scope: the protagonist, N.S. Rubashov (probably loosely modelled after Bukharin), is arrested for 'counterrevolutionary crimes', and spends the rest of the book in prison, being interrogated and prepared for the inevitable show trial. This of itself is not particularly clever, but that is not the core of the book.
The real core of the book is Rubashov's fundamental theoretical paradoxical position: all his life he has believed in submitting the "subjectivity" of the individual to the demands of the Party, in the knowledge that they were building a future for mankind. All his life he has believed in History working its will, in the inevitable eventual victory of the right over the wrong. Yet now this same history has taken a turn, and he and the works of his generation are destroyed by the progeny of his own revolution. His interrogators, first the cynical intellectual Ivanov and later the farmer's son-turned-cadre Gletkin, want him to sign a series of damning confessions that are palpably false, which all parties involved know. Yet if the Party demands this of him, if this indeed is the will of History, can he resist? And moreover, how is it possible to begin with that the revolution led to the terror of "No. 1", the totalitarian Party leader?
Through a series of short but thrilling scenes in interrogation and longer periods of reflection, monologue interieure, and flashbacks, the downfall of a committed revolutionary and intellectual and his generation are painted as vividly and profoundly as one could demand of literature. This book is more powerful than Orwell's "1984" and yet more understanding than any of the common anti-communist works of the last century; it is a testament, dedicated to the generation of Bukharin, Rykov, Tomsky, Rakovsky, Zinoviev, Kamenev, and all the other fighters for socialism at the birth of that bloodiest of centuries.