Agatha Christie (1890-1976) was known as the "Queen of Crime" and her two most famous creations are the deceptively sharp-minded spinster Miss Marple, and the irascible but kind-hearted Belgian, Hercule Poirot.

The latter features in "Murder on the Orient Express" (originally published in 1934) which provides an interesting twist on the "locked door" murder, as all the passengers are ensconced in the famous train. Whilst aboard, Poirot encounters a rude businessman called Ratchett, and refuses to act as his protector. He hears a noise in the night and awakes to find that Ratchett has been murdered. In his usual analytical way he interrogates and delves into the psyche and motives of the other passengers, a varied collection of people including a doctor, a princess, and an actress.

He discovers (spoiler alert!) that they acted in collusion to kill Ratchett, who was the murderer of a little girl called Daisy Armstrong, and avenge her.

The story has many similarities to the real-life 1932 kidnapping of aviator Charles Lindbergh's son. The firstborn of a family (both fathers being pilots) was taken from their crib, the ransom paid, but the child still killed. In both instances, the mother was already expecting again. In real life, as in the story, a nursemaid committed suicide, Christie also drew on real-life weather conditions that led to the train being stranded in the snow.

It has been filmed many times, and also been televised with David Suchet as Poirot.

More Info: en.wikipedia.org