Agatha Christie wrote many books and stories, in some of which she expressed her political views. She believed in conspiracy and was fearful of rich people who became politically powerful. She also had other fears and concerns which may have played a role in her stories. These views are prevalent throughout her work.
Recommended reading: The Secret Adversary (1922) The Big Four (1927) N or M? (1941) They Came to Baghdad (1951) Destination Unknown (1954) Passenger to Frankfurt (1970)