Cousin Bette is a poor spinster and a frequent, welcome visitor at her cousin, Baron Hulot's household. Baron Hulot's daughter, Hortense teases Bette about her "lover", the sculptor, Count Steinbock, who lives above Bette's apartment and who Bette rescued from suicide. Bette treats Steinbock maternally but loves him with a jealous affection and has also invested in him financially. When Bette hears Hortense is engaged to Steinbock she feels betrayed and furious. She resolves to destroy the entire Hulot family with the aid of her neighbour, Madame Valerie Marneffe. Together they wreak vengeance using Valerie's beauty and Bette's wily brain.