Title: Poison in the Pen (Miss Silver #29)
Description: A series of cruel letters upends life in a small village, and Miss Silver searches for the anonymous scribe.

It is through her friend Frank Abbott, of Scotland Yard, that Miss Silver first learns of the anonymous letters. A widowed cousin of his, living in a small country village, is being tortured by an unknown author who insinuates that the young woman’s husband may not have died of natural causes. It is a case of the kind of cruelty that is all too common in the countryside, and the governess-turned-detective listens with only polite interest.

Then the first death comes. Another target of the letter-writing campaign, tortured by the threats to reveal her darkest secrets, drowns herself in the manor-house pond. The Yard sends Abbott to unmask the sinister letter-writer, and he brings Miss Silver along as an undercover agent, masquerading as a tourist as she attempts to stop the next death before it happens.

Miss Silver Mystery #30
Subjects: Women private investigators--England--Fiction, Mystery fiction, Silver Maud (Fictitious character)--Fiction, Fiction, mystery & detective, general, Silver, maud (fictitious character), fiction, Maud Silver (Fictitious character), Women private investigators, Fiction, Large type books, England, fiction, London (england), fiction, Fiction, mystery & detective, women sleuths, Mystery, Miss Silver (fictitious person)
Places: England
People: Miss Maude Silver
Time periods: Written in 1957