This is a later Christie novel, published in 1965. By this time, Christie was an old lady, her attitudes and tastes dated. An ideal time to write a Miss Marple novel!
Miss Marple is on holiday in London, at old-fashioned Bertram's Hotel, which she remembered from her youth. Still Victorian in atmosphere. it has well-disciplined staff and many elderly patrons. Miss Marple encounters a childhood friend there, Lady Selena Hazy, and is intrigued by her fellow guests - famous adventuress Bess Sedgwick, young Elvira Blake, an heiress, and her guardian Colonel Luscombe, and Canon Pennyfather, who is about to attend a conference in Lucerne. He has a misadventure when he goes to Lucerne on the wrong date and is knowcked unconscious in his room when he returns.
Bess Sedgwick turns out to be Elvira's mother., They are both in love with the same man, racing driver Ladislaus Malinovski. Also involved is the hotel commissionaire, Michael "Micky" Gorman, who has a a link with Bess Sedgewick's past.
The complex plot is managed well by the author, and with her usual ingenuity she unveils secret after secret until the true murderer is unveiled. She displays her usual strengths - her characters are interesting and she is psychologically shrewd, so that the action develops from the strengths and weaknesses of her characters. In her lifetime, she was notorious for making the most unlikely character the murderer; it became a joke. In fact, it is said that she wrote her books up to the last chapter, then decided which the most unlikely character was and then rewrote and adjusted sections of the book so that this person was finally revealed as the killer. I leave you to judge whether she did that in this book.
Miss Marple does not play a large part in this book. As so often happens in the Miss Marple books, she is an unobtrusive, sharp-eyed observer of the other characters, quietly putting two and two together.
This is an enjoyable story, perhaps pretty unlikely in places and maybe a bit contrived. The Bertram's Hotel atmosphere is well-created, dominating the book. Typical Agatha Christie entertainment!