1937 - 1939 Paris

After being set free form the Spanish jails, Koestler returned to his previous activity, working as a journalist for the London News Chronicle. As a journalist, he paid a visit to Paris, Athens, and briefly returned to Palestine. Moreover, he set at work at his book, The Gladiators, which he had started a few years before but that was still to be finished.
On his return to Great Britain, just after the publication of Spanish Testament Koestler started a lecture tour on behalf of the Left Book Club. It is in this lectures that for the first time Koestler broke off publicly and explicitly with the Party's line. This happened when, at one of these meetings, a question was asked about the POUM. The POUM, a small Leftist group that had bravely fought in Spain (Orwell had been wounded while volunteering in its ranks) felt in disgrace with Moscow because of its political unorthodoxy. Its leader, Andres Nin, was and his strictest followers were later shot, presumably by Moscow orders, but already at that time they were denounced as Franco's agents and were considered by the Communists as enemy number one because of their Trotskyist leaning.

The first time it was asked, the question took me unawares ... For a moment, my mind was a blank ... Then, without conscious reflection, I took a plunge and said what I really thought. I said that I disagreed with the policy of the POUM for a number of reasons which I would be glad to explain, but that in my opinion Andres Nin and his comrades had been acting in good faith, and to call them traitors was both stupid and a desecration of the dead ...
There was a short, embarrassed silence ... Every time the question cropped up at other meetings, I gave the same answer, and every time it was received with the same embarrassed silence ...

This might seem a detail in today's views, but was an heresy for a Party member, and more than enough for an expulsion. In the meanwhile, the last great wave of show trials took place. Bukharin, Yagoda, Rakovsky and other old Bolsheviks were under trial for having collaborated with the Gestapo to undermine the Soviets. They where found guilty and shot. Stalin had managed to be the only survivor of the great man of the Revolution, all persons that where looked upon as heroes by Koestler and by almost any other "fellow traveller" in the West.

When Koestler was asked to give another lecture about Spain to the Association of Exiled German Writers, he was approached by a Party official asking him to introduce a passage denouncing the POUM as agents of Franco. Koestler refused, and also refused to have the text of his lecture checked beforehand by the Party.
The lecture was concluded by three sentences that were to be a shock to the faithful Communist majority in the audience:

No movement, party or person can claim the privilege of infallibility.
It is as foolish to appease the enemy as it is to persecute the friend who pursues the same end as you by a different road.
In the long run, a harmful truth is better than a useful lie

Koestler decided to anticipate the Party's expulsion, and on worked through the following night on his letter of resignation.

He was now ideologically free to follow the course of his thoughts, and The Gladiators took now more clearly the form of a reflection on means and ends in a revolution.

In the meanwhile, he was contacted by an old friend of his, Eva Weissberg, who had just been expelled from the Soviet Union. She informed him that her husband, Alex was in a Soviet GPU prison accused of being spying for the Germans and fomenting a counter-revolution. The Weissbergs had been living in Kharkov since 1931, Koestler was for long time their guest there, and Alex, a Party member, was a physicist working in a Kharkov plant. Koestler helped Eva in launching a campaign to save his life, and had several letters written to Stalin by eminent scientists and Nobel Prizes from all the world, such as Einstein and Joliot-Curie. Alex's history, together with Koestler's experiences in Seville, was probably the germinal idea for Koestler's next novel:

The novel, as outlined in a short synopsis that I wrote for the publishers, Jonathan Cape, was to be about people in prison in a totalitarian country. There were to be four or five characters who, under sentence of death, re-value their lives; each one discovers that he is guilty, though not of the crimes for which he is going to die. The common denominator of their guilt is having sacrificed morality to expediency in the interest of the Cause. Now they too must die, because their death is expedient to the Cause, by the hands of men who subscribe to the same principles. The title of the novel was to be the The Vicious Circle.

The novel, published under the title Darkness at noon was to mark Koestler's fame and success (incidentally, was also to put an end to Koestler's financial problems and therefore to Dr. Costler's activities)
The political events precipitated. In august 1939 Ribbentrop and Molotov signed the Nazi-Soviet pact of non-aggression Shortly after the Germans invaded Poland, and France declared war on Germany. WWII had exploded.
Koestler's position in France, like the one of all other Communists or former Communists, was delicate. If Communists were faithful to Moscow and Moscow was an ally of Germany, then every Communist was potentially a spy. Moreover, Koestler, after Austria's annexation to Germany, was technically a German.
Every attempt to make his situation clear or to migrate to Great Britain was useless, and after a few days Koestler was arrested and transferred to interment camp of Le Vernet.
Koestler spent about five months in Le Vernet, and at the end his influential friends in London managed to have him released. His experiences in Le Vernet later gave him the material for The Scum of the Earth.
Koestler arrived in Paris hoping to manage to get a passage to England, but there he was stuck in bureaucracy, with no-one wanting to take a position on his case.
France's war against Germany proved a complete disaster. The Nazis almost completely invaded France, and soon an armistice was asked. In that same day Koestler, fearing for his fate should he fall into Nazi hands and inspired by Le Grand Jeu, a movie where Jean Gabin enrols in the Foreign Legion to escape the police, decided to do the same and became the Legionnaire Albert Dubert.
After some more adventures in the chaotic post-armistice France Koestler joined three British soldiers that had been captured by the Germans and had escaped to Marseille. They found the way to have false papers and found a passage to Casablanca and thence to neutral Lisbon.
Again, all his efforts to gain an entry visa to Great Britain turned useless (the couple of months he spent there gave him the main atmosphere for his later book Arrival and Departure) and at the end Koestler decided to fly to Britain without visa to face interment.