Billie Whitelaw dominates this crime melodrama, not as a criminal but as vengeful bystander Jackie Parker. Parker's husband, an armored car driver, is killed during a carefully orchestrated robbery. The police have an idea of who's responsible, but they lack proof. On her own, Parker goes after the suspects one by one, using psychological torture (phone calls, poison pen letters) to break them down. She reduces inside man Pearson (William Lucas) to a quivering mass of gelatin, and indirectly sends Monty (Kenneth Griffith) ...