The Problem of the Wire Cage by John Dickson Carr first appeared in 1939. It's a novel renowned for a tantalising "impossible crime" puzzle, tailor-made for that Chestertonian sleuth, Dr Gideon Fell. The eponymous "wire cage" is, in fact, a tennis court, with a clay surface that is surrounded by a wire fence and also poplars and a yew hedge - an ingenious variation on the classic "locked room".
Frank Dorrance is engaged to be married to Brenda White, a typically attractive Carrian heroine. Dorrance, alas,is an arrogant fellow, much less worthy than Hugh Rowland (a typically decent, yet sometimes rather irritating Carrian hero) who yearns in vain, or so it seems, for Brenda's affection. There's a financial motive for the match - Frank and Brenda are destined to inherit a fortune if they tie the knot, and Brenda's guardian, the wheelchair-bound Dr Nicholas Young, is keen to secure her long-term welfare.
Dorrance is duly found strangled, by his own scarf, in the middle of the tennis court. Heavy rainfall has left the surface muddy, and footprints to and from the body seem to incriminate Brenda. Yet surely the lovely young woman cannot have killed the man to whom she was betrothed? On the other hand, if someone else was responsible, how they did manage to murder Dorrance?
This is, first and foremost, a howdunit; guessing whodunit is much more straightforward, even though I felt the motive was not entirely convincing. The plot is ingenious, and so are the false solutions that Carr offers to tease the reader. An acrobat duly makes an appearance in the later part of the story, and a fresh line of enquiry develops before a second murder -not very satisfactorily conceived - takes place. I confess to having reservations about several aspects of this story (including the rather peripheral part played by Fell, but to say much more would be to risk giving spoilers). However, the breathtaking nature of the central murder scenario makes the book, despite those flaws, well worth reading.