The Third Girl by Agatha Christie

I am not sure if I have seen this novel converted to a film. It is a good mystery which begins with a young lady barging in to see Poirot just as he was finishing his breakfast. She says, she thinks, she may have murdered someone. When pressed to explain what she means, she suddenly turns reticent and says Poirot is too old to be of any help and rushes out. 

Saddened to think of himself as a too old, he accepts the invitation by his friend, the mystery writer Mrs Oliver, to tea, to cheer him up. When Poirot tells her about the young lady who had visited him and what had happened, Mrs Oliver states that she might have met this person at a party she went to recently. So she describes the party and the people and their background. The young lady she feels certain is the daughter of this rich business man who has returned from South Africa with a younger second wife. He had inherited the business from his brother. The daughter has moved out to live in London with 2 other young women. The father is living with his uncle until they can find a place of their own in the city. Meanwhile, it is suspected that the step mother is being poisoned. 

So Mrs Oliver decides to go find out what the young lady is up to by visiting the flat in London. Poirot wangles an introduction and visits the father’s home so see what he can find out about the family. What is the mystery? The young lady has gone missing and the father hires Poirot to find his daughter. He is seemingly writing big checks to buy off his daughter’s unsuitable boyfriend. Mrs Oliver finds the young lady meeting her boyfriend, purely by chance, and tries her hand at detecting by following the boyfriend, after she has called Poirot. All she gets for her trouble is a conk on the head and concussion. 

Poirot is sure there is something much more sinister going on and is determined to find out what is happening. There is something not right with the ‘third girl’ in the flat. Was it a coincidence that the first girl is the secretary of the business man? The second girl is an arty type who works in a fashion and occasionally models and hangs out with new painters. Is there any connection to the death of an old lady in the same block of flats? Also why is the third girl so very confused? Why can she not remember if she did or did not murder someone?

This intrigue is well set and yes once again it is not an easy puzzle to solve. It is indeed a mystery as to what really is the mystery right until the last chapter when Poirot reveals the whole truth. I really good read.