Darkness at Noon by Arthur Koestler

mass market vintage paperback 

 Darkness at Noon (German: Sonnenfinsternis, lit. 'Solar eclipse') is a novel by Austrian-Hungarian-born novelist Arthur Koestler, first published in 1940. His best known work, it is the tale of Rubashov, an Old Bolshevik who is arrested, imprisoned, and tried for treason against the government that he helped to create. WIKI