Before the credits, an off-screen, voice-over narrates:
In the summer of 1953, it was announced that an atomic bomb of foreign origin had been exploded somewhere outside of the United States. Shortly thereafter it was indicated that this atomic reaction, according to scientific reports, originated in a remote area in North Pacific waters, somewhere between the northern tip of the Japanese Islands and the Arctic Circle. This is the story of that explosion.
In 1953, renowned French scientist Professor Montel (Victor Francen) goes missing. The authorities believe that he and four other scientists defected behind the Iron Curtain.
Meanwhile, former U.S. Navy USS Bowfin submarine commander Adam Jones (Richard Widmark) arrives in Tokyo after receiving a mysterious package containing $5000. Jones meets Professor Montel and his colleagues, a group of scientists, businessmen, and statesmen who suspect the Communist Chinese are building a secret atomic base on an island somewhere north of Japan. They want proof, so Montel offers Jones another $45,000 if he will command an old World War II-era Japanese submarine being overhauled and follow the Chinese freighter Kiang Ching, which has been making suspicious deliveries in that area. Jones reluctantly agrees, providing he is allowed to hire some of his former navy shipmates.
The day before Jones is to conduct a test dive, news arrives that the Kiang Ching has sailed. Despite Jones's protests that the torpedo tubes he insisted upon installing are not operational, Montel demands they start out after her. When Montel boards with his beautiful assistant, Professor Denise Gerard (Bella Darvi), the superstitious crewmen are upset, believing women on a ship are bad luck, but Montel insists she come along.
On the voyage, they are detected by a Chinese submarine. When contacted, the Chinese are not fooled by their explanation that they are on a simple scientific expedition and fire torpedoes at them without warning. Unarmed, Jones dives to the sea bottom, hoping to hide there; the Chinese follow. After several tense hours of waiting each other out, Jones finally decides to surface. When the other submarine does the same, Jones rams and sinks it.
Jones wants to turn back, but Montel points out that their contract specifies that he won't be paid unless Montel is satisfied. They follow the Kiang Ching to an island. Jones and Montel land to investigate, but Montel is disappointed by the low radioactivity levels he detects. After a firefight with Chinese soldiers, the patrol returns to the submarine with a captive. They learn the location of another island from the prisoner, a pilot named Ho-Sin.
During a storm enroute, Montel is injured. Because he is too hurt to go ashore, Montel insists Jones take Denise in his place, since she is the only other person qualified to gather and interpret the data. Denise detects an extremely high level of radioactivity; then she is forced to shoot and kill a Chinese solder who stumbles upon her.
Back aboard the submarine, Jones is worried because he recognized an American B-29 bomber sitting on an airstrip. Needing more information, they trick it out of Ho-Sin by putting the ship's cook Chin Lee (Wong Artarne), dressed in a Chinese uniform and beaten by Jones at Chin Lee's insistence, into the same room. Fooled, the captive reveals that the plane is going to drop an atomic bomb on either Korea or Manchuria the next day, with the blame placed on the United States, but Chin Lee slips up and Ho-Sin beats him to death before Jones can intervene.
Jones decides to go ashore and watch for the bomber's takeoff. When he signals, the submarine will surface and try to shoot it down. However, Montel sneaks onto the island in his place. When Jones scolds Denise for not stopping the old man, she tearfully reveals that Montel is her father. The plane is shot down, but it crashes on the island, detonating the atomic bomb and killing Montel. Jones recalls that Montel had said earlier that "Each man has his own reason for living and his own price for dying."
Fuller used contacts to spend several days abourd a US Navy submarine including fifteen hours submerged. The results of the experience led to Fuller adding sequences to the film where Francen gets his fingers caught in a hatch, using a submarine's red lighting for a love scene, and having a battle between two submarines staged similar to a murderer lying for his prey.. When cinematographer Joseph MacDonald said there was no room on the sets for the red lights, Fuller said that few in the audience would be familiar with equipment inside a submarine and to place them in the audience's view that MacDonald did.
The United States Government, who provided the footage of the opening nuclear bomb explosion that started the film insisted that certain colours be erased from the sequence lest it "could reveal nuclear secrets".
The film did excellent box office in the United States and abroad particulary Germany. Later when filming a cameo in Steven Spielberg's 1941 (film), Spielberg showed Fuller that he actually carried a print of Hell and High Water in the boot of his car.
Initially, France banned the film on political grounds. A journalism article noted that France also had banned Soviet political films, and that a number of European countries are sensitive to films with political themes and refuse them exhibition permits rather than rouse the ire of either the U.S. or Russia.
Darryl F. Zanuck often screened his fifth film in Cinemascope to directors who had reservations about working in the process saying "if we can use it on this we can use it on anything". Fuller engendered a feeling of claustrophobia in wide screen.