Conversation so far:
What were some of Agatha Christie's first novels?
Agatha Christie wrote her detective novel, The Mysterious Affair at Styles, featuring Hercule Poirot, a former Belgian police officer noted for his twirly large magnificent moustaches and egg-shaped head.
Was The Mysterious Affair at Styles by Agatha Christie successful?
This first mystery novel by Agatha Christie was well received by reviewers.
Who is Hercule Poirot?
Hercule Poirot is a fictional Belgian detective, created by Agatha Christie. Poirot is one of Christie's most famous and long-running characters.
Was Poirot a character in one of Agatha Christie's books?
Poirot is one of Agatha Christie's most famous and long-running characters, appearing in 33 novels, one play, and more than 50 short stories published between 1920 and 1975.

Question: What is another of her first novels?
Self-contained rewrite: What is another of Agatha Christie's first novels besides The Mysterious Affair at Styles?