The Widow's Club — Dorothy Cannell

Stylish, amusing, and deliciously wicked -- a superb murder mystery from the acclaimed author of The Thin Woman
 
Divorce can end a marriage. Murder can do it better.
 
Meet Ellie Haskell, née Simons, thin woman, newlywed, potential murderess. Her life in charming Chitterton Fells promises nothing but endless bliss -- until she meets two of the most cunning and unlikely private eyes ever to track down a diabolical killer. Misses Hyacinth and Primrose Tramwell of Flowers Detection Agency have been called in by a major insurance company to investigate the deplorably high incidence of sudden death among the married men of this picturesque municipality. The spinster sleuths soon discover that all the husbands had been unfaithful and their deaths neatly arranged by an enterprising social organization called The Widows Club.

But to find the mastermind behind this insidious ring, the Tramwells need an unhappy and betrayed wife. Enter Ellie, who will endanger life and husband to join The Widows Club and arrange to have her dearly beloved . . . dead.