An elderly woman is found murdered in her home. Her lodger, an unpleasant young man, if convicted of the crime, but the police officer in charge of the investigation believes he is innocent and recruits Ercule Poirot to prove that the convicted man is innocent.
Agatha Christie always surprises me when it comes to the identity of the criminal and this time is no exception, which is why I come back to her works again and again. I suspected everyone but the real villain and while many of the characters I pegged as untrustworthy were in fact hiding something (some even concealing secrets related to the case) none of them turned out to be guilty. I particularly enjoyed the characters in this story - the apple-eating authoress, the disheveled hostess, the clingy mother who isn't as weak as she'd like everyone to believe, a publicity-conscious politician, an impoverished nobleman turned farmer, a wealthy heiress who acts like she's the maid... Even if you can't be bothered to keep all the names straight you will know exactly who's who.
One of the themes of this novel is revealed in the alternative title - Blood Will Tell. The notion that character traits are hereditary comes up in conversation and the murder, when discovered, exclaims "I can't help it! It's in my blood!". While there is a reason the saying "the apple doesn't fall far from the tree" exists I don't subscribe to the idea that one's predecessors' flaws as well as their strengths are irrevocably a part of one's character and feel that Christie didn't either.