À la folie ("To Madness") is a 1994 French drama film by Diane Kurys with music by Michael Nyman. It entered the competition at the 51st Venice International Film Festival.

Plot

Two rival sisters, Alice and Elsa, have been apart for two years. Alice, a promising young artist, lives in an attic flat in Paris. Her lover Franck, a boxer, has just moved in with her. Problems for the happy couple ensue when Elsa, a bored housewife, suddenly appears unannounced at their door after leaving her cheating husband Thomas and their two children, and a menage-a-trois develops. Elsa immediately begins trying to dominate their lives. Alice wants the out-of-control Elsa, who disrupts their life by playing psychological games with them, to leave, but then suddenly changes her mind, unable to bring herself to throw Elsa out. To thank her, Elsa destroys her art studio, has sex with Franck, convinces him that Alice is unbalanced, and then ties Alice up in her apartment.