Moffett's Wife: and her mysterious collapse

The story takes place in Milan, Italy. Marcella Algani is married to American Jason Moffett. Her son Michele is convicted of killing his business partner Gianni Brambilla and is sentenced to a term at San Vittore prison. Marcella knows that he didn't kill Brambilla but there are no leads to who really did it or why. She is convinced that it is someone local, someone in their circle of friends and acquaintances. She decides to fake a stroke-like attack and pretend to be catatonic with the hope that someone will say something incriminating within earshot of her thinking that her mind is gone. The plot works and with the help of Michele's genius friend Alberto they find out that the company is being robbed and was discovered by Brambilla. They killed Brambilla to prevent him from exposing them. They also kill a detective Marcella hires to investigate. The criminals also try to kill Michele and Alberto to prevent being discovered. Thinking her mind is gone, her unexpected testimony in court helps convict the criminals.