Premise: Uncommon Danger is the second novel by British thriller writer Eric Ambler, published in 1937. In his autobiography, "Here Lies", Ambler explains the original title was "Background To Danger", but his British publisher disliked the word 'background', so it was published in all English-speaking countries except the US as "Uncommon Danger".
Hypothesis: Uncommon Danger was a book written in the 1940's