The Mystery of the Blue Train by Agatha Christie

Ruth Kettering is unhappy. She didn't marry her first love, her millionaire father ran him off. But her current husband seems to be no better, flaunting his affairs, running through her money. Even the fabulous, though possibly cursed, necklace that her father gifts her doesn't make her happy. She boards a train to the Riviera anyway but doesn't survive the trip. Her father hires Hercule Poirot to figure out what, exactly, happened.
A lot of the story is told from the third person limited narration focusing on Katherine Grey. Miss Grey has long been a companion and has inherited a tidy sum from her last employer. She is on the same train and actually interacts with Ruth.
An interesting story but not as fairly clued as many in the Christie ouvre. 

Three and a half stars

This book came out March 29, 1928

Follows The Big Four

Followed by The Underdog and Other Stories

Borrowed as audiobook from Hoopla

Opinions are my own