The heroine of this story is Anne Beddingfield, is a fiesty young woman in the Tuppence Beresford mould. Her father dies leaving her not very well provided for and Anne finds herself living off the kindness of
friends. This is not a situation which suits her, she is an independent spirit and as soon as she gets the first sniff of adventure she's off.
She happens to witness what seems to be an accidental death on the London Underground. Anne suspects it's something more, and believes a note she finds on the station platform, '1 7 1 22 Kilmorden Castle' is a clue. The dead man is linked with an empty property in which a murdered woman has been found. Anne finds out that 'Kilmorden Castle' is the name of a ship which is due to sail from London to South Africa. On a whim Anne spends all her money on a one way passage on the ship in order to uncover the mystery.
I found this story very convoluted and complicated. I certainly had no idea who the villain was. It relied quite a lot on co-incidence, which is fine, but I think it added to my confusion. I have promised myself that the next time I read a Christie I'm going to make proper notes, hopefully that way I'll be able to keep it clearer in my head.