John Dickson Carr (1906-1977) was an American author of detective stories, who also published under the pen names Carter Dickson, Carr Dickson and Roger Fairbairn.
The son of a US congressman, Carr lived for a number of years in the UK and he married an English woman. Many of his novels had English settings, his best-known detective characters were English, and he is sometimes described as a 'British-style' mystery writer. He is known as one of the greatest writers of the 'Golden Age' mysteries, which were complex and plot-driven with a great puzzle at the core of the story.
His The Hollow Man (1935) was selected in 1981 as the best 'locked-room' mystery of all time by a panel of 17 mystery authors and reviewers.
One of his books was set in Torquay.
This was The Punch and Judy Murders (also known as The Magic Lantern Murders). It was published under the name of Carter Dickson and features the detective Sir Henry Merrivale.
Here's the storyline:
Kenwood Blake is about to marry his fellow British Secret Service operative, Evelyn Cheyne. He is sidetracked by an urgent telegram from Sir Henry asking him to come to Torquay to go undercover to investigate a suspicious German ghost hunter and spiritualist. It's believed a German spy known only as 'L' is in the town.
However, the chief suspect is soon found dead in his easy chair, grinning from the rictus of strychnine and wearing a Turkish fez''. Another German suspect is also murdered across town. The hero and his fiance then race around Torquay avoiding the police while investigating espionage, counterfeiting, spiritualism, and multiple impersonations. Eventually, the murderer is revealed just in time for the wedding to take place.