Big Cube, The

Adriana Roman is a former actress who marries a wealthy tycoon Charles Winthrop, who dies in a boat accident off the Mexican coast. Winthrop's daughter, Lisa, whom despises Adriana, plot to drive her insane with drugs so she and her drug-addict boyfriend, Johnny, can marry and inherit all the money for themselves. When a Broadway playwright, named Frederick Lansdale, and a close friend of Adriana suspects something, he tries to rescue Adriana from the mental hospital where she gets committed and redeem Lisa before Johnny can double cross her. (official distributor synopsis)