Three Act Tragedy by Agatha Christie

The stage is set in the first chapter. We meet some of the main players: Sir Charles Cartwright who owns the Crow's Nest in Loomouth, Cornwall; Sir Bartholomew Strange, neurological physician; and Mr. Satterthwaite, our stand-in for Hastings but who is so much more perceptive about human nature than Poirot's usual sidekick.
A dinner party is to be held but an unlucky number of people have been invited. And one dies. The Reverend Stephen Babbington who is fairly innocuous. Though Sir Charles loudly proclaims "Murder!", no one else agrees. Even Hercule Poirot who is present at the party.
However, there is later another dinner party, one where many of the same people gather. This time, it is Sir Bartholomew who dies. It is discovered that he died by nicotine poisoning. Suddenly, it seems that Babbington may have been murdered as well. 
THough this is a Poirot book, we don't see much of him until 54% of the way through the story. However, we do get a lot of third person omniscient from Sir Charles Cartwright, Mr. Satterthwaite, and the young Miss Lytton Gore who are investigating the mystery. The ending is masterfully crafted and there are clues planted along the way that make sense once the murderer is revealed.  

Four stars

This book came out June 1, 1934

Follows Murder on the Orient Express

Followed by Death in the Clouds

Borrowed as audiobook from Hoopla

Opinions are my own