Helen Clarvoe is a 30-year-old spinster living in a hotel in Hollywood. When she receives a sinister telephone call from Evelyn Merrick, an acquaintance she can't remember, Helen turns to her financial consultant, Paul Blackshear, for help.
Blackshear begins investigating why Evelyn is threatening Helen and quickly discovers just how thin the veneer of respectability is in the Clarvoe family. Helen's mother is obsessed with keeping up an image of wealth and beauty, while her servants go unpaid and she looks "...pale and cold, a starved sparrow preserved in ice." Helen's brother Douglas, the most likeable of the characters apart from Blackshear, spends his days swanning around in beaded moccasins and a bathrobe, hiding his frustrated homosexuality from his doting mother.
Helen, who inherited her father's extensive wealth, has her own problems. Always the plain one, always the shy one, she now lives the life of a recluse with no friends and no contact with her remaining family.
This book is not just a crime novel. It's the study of an unstoppable descent into madness, with moments of chilling terror. Like Christie's 'Ten Little Niggers', the ending reveals a shocking solution to the mystery that should have been obvious, but wasn't. Considered one of Millar's best novels, the review on the back of the pictured paperback copy sums it up perfectly: "...a glimpse of bright-eyed madness as disquieting as a shriek in the night."