The Box Office Murders and The Purple Sickle Murders were the original British and American titles of a novel by Freeman Wills Crofts which has now been reprinted as Inspector French and the Box Office Murders. It was first published in 1929, and although it's a murder mystery, it's not a typical Golden Age whodunit but rather a lively thriller set mainly in London.
Inspector French is consulted by a young woman called Thurza Darke (great name!) who works as a clerk in a box office. She has got herself into a tricky situation with an unscrupulous bunch of people, and seeks his guidance. He is impressed by her manner, and arranges to meet her at the National Gallery, but she doesn't turn up. Unfortunately, her body is soon found, and it appears that someone has drowned her.
French, I thought, was rather remiss in not having the girl watched for her own protection, but clearly the police did things differently in those days. I was surprised when French later indulges in burglary of a suspect's premises, and even more startled when he not only breaks in somewhere else, but enlists the support of a subordinate and the subordinate's young son in so dong. Blimey!
But these quibbles don't matter, and I enjoyed the story. It's quite fast-moving, and Crofts cleverly obscures the reality of the criminal scheme of the gang of murderers responsible for killing several young women who worked as box office clerks. Not an orthodox police procedural, by any means, but a very welcome reprint, not least because it illustrates that Crofts was a more versatile writer than he has often been given credit for. His literary style may have been plain, but I must say that the more of his work I read, the more I appreciate his considerable skills as a plotsmith.