Ransom Money (1970)

A strange kidnapping at the rim of the Grand Canyon sets the action in motion in RANSOM MONEY. An unseen mastermind, as brilliant as he is cruel, has abducted the only son of a wealthy widower. Using the most sophisticated electronic devices available, the kidnapper manages to elude the police - and coerce the widower to pay his million dollar ransom. That is, until Broderick Crawford, playing a hardened L.A. detective, uses the kidnapper's own genius to foil his plan in one of the most bizarre twist endings on record.