Spinsters in Jeopardy is a detective novel by Ngaio Marsh; it is the seventeenth novel to feature Roderick Alleyn, and was first published in 1954. The novel is set in Southern France, where Alleyn, his painter wife Agatha Troy and their young son Ricky are holidaying, although Alleyn is also tasked by his Scotland Yard superiors with meeting French police colleagues to discuss international drug trafficking through Marseilles. On the overnight sleeper train from Paris, the Alleyns witness what appears to be a fatal night-time stabbing in the illuminated window of a dramatically-set mediaeval castle overlooking the railway line. This proves to be the resort of an élite, louche group of socialites who are dabbling in Black Magic under the auspices of a smoothly dubious host and 'high priest