Complex sentence: With the help of socialite Patricia Longworth (Selena Royle), Castleman grooms Ethel in the arts of cultured living, makes her his mistress and tries to use her to trap his arch-rival Nick Prenta (Steve Cochran).
Split into simpler sentences: With the help of socialite Patricia Longworth (Selena Royle), Castleman grooms Ethel in the arts of cultured living. After making her his mistress, he tries to use her to trap his arch-rival Nick Prenta (Steve Cochran).