On a perfectly ordinary day, the management of an airline receives a note demanding a half-million dollars from someone who claims to have put a bomb aboard one of their planes. When the device, a tiny but dead electronically-triggered explosive, is found, they're told that there's another -- the FBI and the news media are all present as it is retrieved. One of those who sees the drama unfold on the news is Paul Molnar (James Mason), an electronics expert, who suddenly finds himself in the middle of a nightmare along with the rest of his family-- he and his wife (Inger Stevens) and their young daughter are kidnapped by Paul Hoplin (Rod Steiger), a former army buddy of Paul's, who duped him into designing the devices, and now wants Molnar's wife to act a courier for the money. With her husband and daughter in the hands of two of the gang (Angie Dickinson, Jack Klugman), she is made to pick up the money and make her way across New York while a clock is ticking on their lives -- and she must survive being left guarded by Steve (Neville Brand), an ex-con, murderer, and sexual predator, and the least-tightly-wrapped of all Hoplin's gang.
~ Bruce Eder, All Movie Guide