In 1930 Cronin was diagnosed with a chronic
duodenal ulcer and told to take six months' complete rest in the country on a milk diet. At Dalchenna Farm by
Loch Fyne he was finally able to indulge a lifelong desire to write a novel, having previously "written nothing but prescriptions and scientific papers." From Dalchenna Farm he travelled to Dumbarton to research the background of his first novel, using files from Dumbarton Library, which still has a letter from him requesting advice. He composed ''
Hatter's Castle'' in the span of three months and quickly had it accepted by
Gollancz, the only publisher to which he submitted it, apparently after his wife had randomly stuck a pin in a list of publishers. It was an immediate success and launched Cronin's career as a prolific author. He never returned to medicine. Many of Cronin's books were bestsellers in their day and translated into many languages. Some of his stories draw on his medical career, dramatically mixing realism, romance and social criticism. Cronin's works examine moral conflicts between the individual and society, as his idealistic heroes pursue justice for the common man. One of his early novels,
The Stars Look Down (1935), chronicles transgressions in a mining community in north-east England and an ambitious miner's rise to be a
Member of Parliament (MP). A prodigiously fast writer, Cronin liked to average 5,000 words a day, meticulously planning the details of his plots in advance. He was known to be tough in business dealings, although in private life he was a person whose "pawky humour... peppered his conversations," according to one of his editors,
Peter Haining. Cronin also contributed stories and essays to various international publications. During the
Second World War he worked for the British
Ministry of Information, writing articles as well as participating in radio broadcasts to foreign countries. ==Influence of
The Citadel==