Annette Kerner was a private detective. Kerner initially trained as an opera singer, but was drawn into the world of espionage through mixing with the intelligence agents who frequented the clubs she performed at in Geneva and Zürich. She was recruited by the Special Branch as an espionage agent in Switzerland, aged just 17.

On her return to the UK, she opened the Mayfair Detective Agency on Baker St in September 1946, just a few doors down from the famous, fictional 221b – which suited the self-styled ‘Mrs Sherlock Holmes.’

Kerner was one of the first British female sleuths, and she became the first female detective to publish a memoir, Woman Detective, in 1954.