Dr Ringwood, serving as locum tenens for an old friend recovering from appendicitis, returns to his lodgings in a pea-souper so thick he can't even see the pavement. He is looking forward to a cosy evening by the fire with a cigar and the latest issue of the British Medical Journal but alas, it is not to be. Dr Trevor Markfield, a friend who lives locally, drops in for a chat and engages in a bit of gossip, hinting the marriage of Dr Silverdale, under whom he works at the Croft-Thornton Research Institute, is not all it should be. It seems Dr Silverdale's French wife Yvonne has taken up with Ronald Hassendean, an idler who works as little as possible at the Institute and is widely known as her permanent dancing-partner. Naturally there is scuttlebutt. At this point, Ringwood receives a call from a maid anxious about her fellow servant's worsening illness, given the family employing them is out for the evening. Markfield identifies the address she gives as Silverdale's house and guides Ringwood there through worsening fog before leaving for home. Ringwood discovers the house silent, lights on, and the front door unlocked. Venturing inside, he finds a young man shot twice bleeding to death. Then he realises he is in the wrong house. Silverdale's home is next door. The police are summoned and Chief Constable Sir Clinton Driffield arrives with Inspector Flamborough to investigate the matter. The deceased is identified as Ronald Hassendean, his dancing days done. Then the Hassendean's maid is found strangled and the other maid can't be interviewed as she is delirious with a bad attack of scarlatina.
Where to begin? Well, next morning Driffield receives a telegram advising him to visit the bungalow used as a summer residence by the Hassendean family. And what do they find there but Mrs Silverdale, lying dead in an armchair.
In talking to Flamborough about the case, Driffield notes three possibilities to explain these events: accident, suicide, or murder, various permutations of which total eight.
A rich stew of suspects forms. What about motives? Has Silverdale grown tired of his wife's open flirtation with young Hassendean? We might also note Silverdale beat Markfield for the post of head of department. Two other workers at the Institute also come under suspicion: Miss Hailsham, Hassendean's bitter and vindictive ex-fiancee, and Miss Deepcar, due to hints of mutual attraction between her and Silverdale
Then there's Mrs Silverdale's brother Mr Menard, who's attempting to get her to change her will to what he views as a fairer distribution of her recent inheritance. Meaning more should be left to him. But what if she becomes angry at his pressing her on the matter and leaves him nothing under a new will? After all, a small bequest is better than none. Nor should we overlook Spratton, a money lender holding an insurance policy on Hassendean's life as security for his loans to the dead man. Murder rather than suicide or accident would net Spratton a substantial amount.
Investigations are aided by subsequent tips received from the sender of the telegram -- but only if Driffield and Flamborough are able to decipher their informant's coded advertisements in the local papers.
My verdict: I raced through and enjoyed this novel. At times it assumes the polite air of a restrained police procedural during an investigation also featuring forgery, possible blackmail, burglary, impersonation, and a method of murder I believe most readers will find unique. Connington's title states the case has nine solutions and when the ninth is revealed it features a clever double twist. All in all, then, I award The Case With Nine Solutions an A.
E-text: https://www.gutenberg.org/ebooks/72816