Green for Danger is a popular 1944 detective novel by Christianna Brand

Christianna Brand

Christianna Brand was a British crime writer and children's author.- Background :Christianna Brand was born Mary Christianna Milne in Malaya and grew up in India. She had a number of different occupations, including model, dancer, shop assistant and governess...

, praised for its clever plot, interesting characters, and wartime hospital setting. It was made into a 1946 film

Green for Danger (film)

Green for Danger is a 1946 British thriller film, based on the popular 1944 detective novel by Christianna Brand.The book Green for Danger was praised for its clever plot, interesting characters, and wartime hospital setting. The film version, starring Alastair Sim and Trevor Howard, with Sally...

 which is regarded by film historians as one of the greatest screen adaptations of a Golden Age mystery novel.
A murder takes place in a rural British hospital. Inspector Cockrill is tasked to determine whodunit when the head nurse is killed after revealing that the death of a patient under anaesthesia was no accident.