Conversation so far:
When did A. J. Cronin start his writing career?
In 1930 at Dalchenna Farm by Loch Fyne A. J. Cronin was finally able to indulge his lifelong desire to write a novel.
What did A. J. Cronin write about at Dalchenna Farm?
A. J. Cronin composed Hatter's Castle in the span of three months.
What was Hatter's Castle by A. J. Cronin about?
The plot revolves around many characters and subplots, all of which relate to the life of the hatter, James Brodie, whose narcissism and cruelty gradually destroy his family and life.
What year did Hatter's Castle by A. J. Cronin come out?
Hatter's Castle came out in 1931.
What other books did A. J. Cronin write besides Hatter's Castle?
One of A. J. Cronin's early novels is The Stars Look Down.
What was The Stars Look Down by A. J. Cronin about?
The Stars Look Down chronicles transgressions in a mining community in north-east England and an ambitious miner's rise to be a Member of Parliament.
Did A. J. Cronin write any other books besides Hatter's Castle and The Stars Look Down?
The Citadel is a novel by A. J. Cronin, first published in 1937, which was groundbreaking in its treatment of the contentious theme of medical ethics.
What are some international publications A. J. Cronin contributed to?
During the Second World War A. J. Cronin worked for the British Ministry of Information, writing articles as well as participating in radio broadcasts to foreign countries.
Is there anything else interesting about A. J. Cronin's writing career besides his contributions to international publications?
A prodigiously fast writer, A. J. Cronin liked to average 5,000 words a day, meticulously planning the details of his plots in advance.

Question: What was the fastest book he wrote?
Self-contained rewrite: What was the fastest book A. J. Cronin wrote?