The seventies of this century. long and successfully studies dolphins. The truly amazing abilities of these animals, and most importantly - their minds, cause general interest - both in a curious public and in various departments. In the United States, where Professor Seville lives and works, five hundred million dollars are spent annually on dolphinology. And among organizations that invest a lot of money in the study of dolphins, there are many who work for war.

Seville is trying to train dolphins in human speech. Two competing intelligence agencies take care of his work at once; he conditionally calls one “blue”, and the other - “green”. In his opinion, some follow him with a touch of hostility, others with a touch of benevolence. And although Seville is exclusively interested in his work, a natural sense of justice often makes him think about the correctness of the policies pursued by his country and president. This is especially true of the Vietnam War, which the US has been waging for a long time and to no avail.

Both departments know every step of the professor, even how and with whom he makes love. Spying on his personal life infuriates the professor especially: the temperamental Seville, in whose veins a lot of southern blood flows, is divorced and often starts novels, hoping to meet the woman of his dreams. However, it seems that finally he succeeds: his current assistant Arlette Lafey becomes his lover, and then his wife.

In addition to Miss Lafey, Peter, Michael, Bob, Susie, Lisbeth and Maggie work at the Seville station. They are all very different: Peter and Suzy are great workers; Michael is more interested in politics, he is of the left and opposes the war in Vietnam, Maggie is an eternal loser in her personal life; Lisbeth deliberately emphasizes his independence, and Bob is a secret informant of one of the departments.

Professor Seville is making amazing strides: the dolphin Ivan begins to speak. So that the Fa, as the dolphin calls himself, is not lonely, the professor plants Bessie's "dolphin" to him, or, as the Fa says, Bi. Suddenly, the Fa stops talking. The existence of the laboratory is at risk. Then Seville applies the “carrot and stick” method to Ivan: dolphins are given fish only when the Fa asks for them in words. The result is disappointing: the Fa achieves fish with a minimum of words. Then a female is taken from him and a condition is set: the Fa says, and Bi is given to him. The Fa agrees. Now the Fa and Bee training is truly leaps and bounds. .

The work of the laboratory is classified, but enthusiastic Seville does not attach any importance to this. Suddenly he is called "to the carpet." A certain Mr. Adame reproaches the professor for the fact that because of his negligence, there was a leak of secret information - the resigned Elizabeth Dawson gave the Russians secret information about the work of the laboratory and stated that she had done so at the direction of the professor himself. However, Adams knows this is a lie: Elizabeth made a similar statement out of jealousy. However, he very unequivocally warns Seville about the need to be more vigilant, otherwise he will be removed from work. In the end, Seville, hotly attached to his pets, agrees to a compromise: to publish the results of his experiment, but in the form in which he is allowed. Seville is allowed to hold a press conference with dolphins: “they understand” that since the enemy already knows about this work, it makes no sense to keep it a secret further, it is better to make it public in a catchy, pseudoscientific form. Moreover, Sevilla does not suspect for what purposes “there” they intend to use the dolphins trained by him ...

The press conference with the Fa and Bee becomes a sensation. Dolphins intelligently answer a variety of questions: from "What is your attitude to the president of the United States?" to "Your favorite actress?" In their answers, the Fa and Beh show remarkable erudition and an undeniable sense of humor. Journalists learn that dolphins have learned not only to talk, but also to read and watch TV shows. And, as everyone unanimously notes, the Fa and Bee love people.

The United States is embraced by dolphin addiction: press conference recordings are sold out instantly, toy dolphins are sold everywhere, à la dolphin costumes come into fashion, everyone dances ин dolphins ’dances ... And other countries are frightened by yet another scientific achievement of the USA, their government frantically pondering how soon Americans can use the dolphins for military purposes ...

Sevilla writes a popular book about dolphins, and it has been a dizzying success. The professor becomes a millionaire, but he is still passionate about work and leads a modest lifestyle. The trouble comes unexpectedly: in the absence of Sevilla, Bob takes Fa and B away from the laboratory, and the professor is told that this is the order.

Enraged, Seville wants to leave the country, but he is not released. Then he buys a small island in the Caribbean and settles there with Arlette, at his own expense establishes a laboratory and starts working with dolphins again. One of them - Daisy not only learns to speak, but also teaches the professor the dolphin language.

Suddenly, the world is shocked by the news: the American cruiser Little Rock was destroyed by an atomic explosion in the open sea near Haiphong. China is called the culprit of the explosion, anti-Chinese hysteria begins in America, and all immigrants from Southeast Asia are being persecuted. The US president is ready to declare war on China, and most Americans support him. The Soviet Union warns that the consequences of American aggression against China may be irreversible. Adama comes to Seville, He reports that the Fa and Bee have completed some task of the competing department, and he needs to find out what it consisted of. He wants to return the dolphins to Seville under the condition that the professor give him a record of their story. Adame says that, having returned from the assignment, the dolphins stopped talking, and he hopes that Seville will be able to talk to them. He also tells Seville about the death of Bob, who worked with the Fa and B.

Dolphins are brought. Fa and Bee refuse not only to speak, but to take fish from Sevilla’s hands. The professor tries to find out what happened in the whistling language and learns that “the person is not good”.

Another problem arises: Daisy and her chosen one Jim do not want to give up the harbor to new dolphins. Seville takes Fa and Bee to a remote grotto.

At night, the military attacks the island and kills dolphins in the harbor. Everyone believes that the Fa and Bee died, only Seville and Arlette know the truth, but they are silent. Adam comes to see the death of the dolphins and find out if they managed to tell the professor anything. Leaving the island, Adame warns that Seville, most likely, is waiting for the fate of dolphins.

Seville and Arlette go to the grotto of Fa and Bee, telling how they tricked them into blowing up the Little Rock cruiser. Those who sent them did everything so that they died along with the cruiser, and only by a miracle did they manage to escape. They told Bob about everything, but he did not believe them. Since then, they have not been willing to talk to people.

The military surround the island. Seville and Arlette decide to flee to Cuba to tell the world the truth about the actions of the American military. Under the cover of night, they board a boat, with the help of dolphins they silently pass barrage posts and sail through the warm waters of the Caribbean Sea.