"Fear Is the Key is a 1961 thriller novel by Scottish author Alistair MacLean, and a 1972 British film based upon it. Veteran fans of the author will note that MacLean is at his best, with the self-deprecating, sardonic, ironic humor that has come to characterize his writing style.
In the prologue, set in May 1958, Talbot, owner of "Trans Carib Air Charter Co" was in the British Honduras in radio contact with one of his planes en route to Tampa, Florida, as it is being shot down by an American military plane. This resulted in the death of Talbot's son, wife Elizabeth and brother Peter.
Two years later, Talbot has apparently turned to a life of crime, for which he is now facing sentencing in a courtroom. He escapes, taking a young woman hostage. A reward is put out on his head, and he is captured by a thug who turns him in to the hostage's father. Instead of turning him over to the police, however, the father hires him for some not entirely legitimate tasks. The father, it turns out, has been consorting with some shady characters, who may or may not have been responsible for killing Talbot’s family. The story becomes straight action with car chases, gunfights, the mafia, a beautiful woman, mysterious doings aboard an oil rig in the Gulf of Mexico, and a sunken DC-3 at the bottom of ocean with a secret treasure, as Talbot searched for answers to his long quest to find the murderers of his family. In typically MacLean style, the reader comes to find that nothing in this complicated plot is quite as it seems.
Fear Is the Key appeared in film in a 1972 release directed by Michael Tuchner. The protagonist, Talbot, was played by Barry Newman, and the millionaire's daughter Sarah by Suzy Kendall. The movie features a soundtrack by Roy Budd."