An American critic in "Politics" defines the book as "an ingenious use of Marxism for the arrangement of a detective novel." But Koestler asks us to believe that the tragedy, beneath the veil of fiction, is true. For the fiction is not intended to deceive the reader; the book presents no mythical universe, but deals with prewar Russia, with Stalin, with the Trotskyists brought before the Soviet tribunals.

The first clear fact that emerges is that Koestler, in order to describe the Soviet prisons, which he has never seen, draws on his experience of fascist prisons. Side by side with facts of pure invention, there is a considerable amount of striking documentation, taken from the diary of his term in Franco's gaols (for Koestler's first book on this subject, see Spanish Trstament). His cell, his gaolers, his prison are very real; the prison is that of Seville, the gaolers are Falangists, and Roubachov is Koestler in the hands of the Spanish Fascists.

It is all well done, and seizes the attention. But as the story progresses and the pages are turned, the reader becomes uneasy. The reporter gives way before the political philosopher, whose analyses are very open to question.

In so far as Roubachov is a prisoner, he is human, believable, almost likeable. But Koestler constantly takes him in hand to mould him into a Bolshevik, and then his character has the same relation to that of a revolutionary as Eric von Stroheim in Hollywood has to Germans in Germany.

Roubachov, moreover, no longer believes in the revolution: that is his only crime, for if he sinned, it was by his intentions, never by action.