Miss Marple knows her friend is not known to make up stories or see things. If she says someone was murdered, then someone was murdered. She works out where a person would drop a body from a train and decides the only logical place would be Rutherford Hall. Being an elderly lady, she realizes she needs strong bodies with intelligent minds to prove her theory. She enlists the help of Lucy Eyelesbarrow to find the body and Inspector Craddock to solve the crime. Lucy joins the staff of Rutherford Hall, wins the hearts of just about everyone, but she may be closer to the murderer than she realizes.
4:50 from Paddington is the third Miss Marple mystery I've read and I'm getting the impression that she doesn't do a lot of leg work in any of her stories. She's more of a consultant once she sets Lucy and Craddock on the case. I did enjoy the brainy Lucy though. She's a 'professional domestician, or an answer to a prayer' as she puts it. She's like Martha Stewart and Nanny McPhee rolled into a young, attractive package. She saw an opportunity to make a lot of money putting people's homes in order and does quite well for herself. Plus she's fearless (and way too good for any of the men who want to marry her!). It's too bad that 4:50 from Paddington is the only Christie novel in which she appears.
This isn't my favorite of the Agatha Christie novels I've read so far. I was a little disappointed at how things ended and who turned out to be the murderer. That doesn't mean I didn't enjoy it. Christie mysteries are always fun to try and solve.