Rumours have been spread in Sunningwater that young widow Mrs. Dane is actually Felicia Hindermarsh, involved in a tragic scandal following an affair with a married man in Vienna.
This sets Sir Daniel on the right track and he follows up skillfully and mercilessly, finally drawing the confession out of her that she is indeed Felicia Hindermarsh and has taken her late cousin's identity.
Mrs. Dane's Defence was generally well received, though the morals promoted may have seemed old-fashioned by young, more liberal audiences who had seen the plays of George Bernard Shaw or William Archer.
The first, a silent film in black and white, was released in 1918, directed by Hugh Ford, starring Pauline Frederick as Mrs. Dane, Frank Losee as Sir Daniel and Maude Turner Gordon as Lady Eastney.
Bramble and released in 1933, starring Joan Barry as Mrs. Dane, Basil Gill as Sir Daniel and Evelyn Walsh Hall as Lady Eastney.