The Day of the Dolphin is a 1973 American science-fiction thriller film directed by Mike Nichols and starring George C. Scott. Loosely based on the 1967 novel, Un animal doué de raison (A Sentient Animal), by French writer Robert Merle, the screenplay was written by Buck Henry.
Plot – A brilliant and driven scientist, Jake Terrell, and his young and beautiful wife, Maggie, train dolphins to communicate with humans. This is done by teaching the dolphins to speak English in dolphin-like voices. Two of his dolphins, Alpha (“Fa”) and Beta (“Bea”), are stolen by officials of the shadowy Franklin Foundation headed by Harold DeMilo (Fritz Weaver), the supportive backer of the Terrells’ research. After the dolphins are kidnapped, an investigation by an undercover government agent for hire, Curtis Mahoney (Paul Sorvino), reveals that the Institute is planning to further train the dolphins to carry out a political assassination by having them place a limpet mine on the hull of the yacht of the President of the United States.