Spinsters in Jeopardy — Ngaio Marsh

For Inspector Roderick Alleyn, the trip was to be official; for his family, a Mediterranean romp. But a plot torn from the pages of a Gothic novel soon engulfed them all. Alleyn's son was kidnapped. A very wealthy spinster was murdered.

And in an eerie chateau, carved out of the Riviera mountainside, Alleyn faced the ultimate jet-set cult...