The British Library have re-published dozens of Golden Age crime novels, many by authors now largely forgotten. Mavis Doriel Hay wrote three crime novels in the mid-1930s of which this, Murder Underground, was the first.
Like many Golden Age authors her career was cut short by the Second World War and the chaos caused during and after it and she never added to her three novels post-war. Though she did write some non-fiction books in the 1950s and 1970s.
Her first novel Murder Underground, which deals with the investigation (largely by amateurs) of the murder of a woman at Belsize Park tube station, can be best thought of as "promising". The set-up of the story is well done and interesting but unfortunately the story meanders a bit too much with the characters being rather one-dimensional and mostly unlikeable.
Towards the end of the book though it really starts to pick up once the story seems to get some direction and the ending is excellent, it is just a shame the earlier two-thirds of the book are a bit lacking.
Overall though a good enough read, and it has a lovely painting of a 1938 Tube Stock train on the cover!