The first volume, The Gladiators, is about the subversion of the Spartacus revolt, and the second, Darkness at Noon, is the celebrated novel about the Soviet show trials.

The pretence that it is a novel is very thin; in effect it is a tract purporting to show that revolutionary creeds are rationalisations of neurotic impulses".

[2] In a November 1943 review, Saul Bellow wrote that Arrival and Departure "raises the following questions: When we have succeeded in understanding what it is in the growth of our minds, our early histories, that drives us to serve causes, is it then proper for us to abandon those causes?

"[3] Written during the middle of World War II, Arrival and Departure reflects Koestler's own plight as a Hungarian refugee.

"[4]) Reflecting Koestler's later relationship with science and particularly his disagreement with various movements within psychiatry, the main character emerges from treatment psychically neutered, and the critical question of the novel is how much of his later trauma and political activity is due to a small incident in his childhood.