At a little restaurant an attractive waitress is going with a professor but finds out he may be a traitor. Others are interested in her and are also involved in spying.
Slob (Lee Marvin) sees pretty Kotty (Terry Moore) laying on the beach and kisses her. She wakes up and hits him until he lets go of her. He runs off.
George (Keenan Wynn) gets the cash register ready for business at an eating place. Slob complains that “the tomato” is supposed to take care of the dishes. George says her name is Kotty. She comes in and complains about Slob. Professor Sam Bastion (Frank Lovejoy) comes in and tells Slob to get back to work. Sam tells Kotty that Slob is going to buy her a new petticoat. She says she is studying to take the civil service exam. Sam puts his arms around her, and he tutors her in government and kisses her.
In the kitchen Slob and Perch (Len Lesser) box, and George reprimands them. Slob gives him money for some pills. George asks what they were whispering about. George tells Perch to leave. Perch goes out, and Eddie (Whit Bissell) comes in. Eddie says that Slob’s watch had been in soup. Eddie asks for a hamburger. Sam talks with Eddie, who asks him for advice. Kotty is dressed as a waitress and welcomes Eddie. Sam says goodbye and goes out, kissing Kotty outside. Two chicken workers in uniform come in and sit at the counter. When Kotty comes back in, they whistle at her. She says the research facility nearby is important. The two guys leave.
In a back room Slob unlocks a locker and looks at pictures of formulas written down. Then he burns them. At the counter Eddie asks George why he forgot how to laugh. George complains about life, and Eddie reminds him about D-Day. Eddie tells George that he does not fit between Kotty and Sam. George suggests they go to Acapulco. Kotty asks to feel their hands and says it is odd that a truck-driver has soft hands.
George and Slob work out with weights. A man knocks, and George shouts that they are closed until six. George says Slob should work out harder. Kotty comes in, and they put their shirts on quickly. They ask her who has the best legs, and she shows hers as the best.
Sam and Kotty lay on the beach together. He asks her what her secrets are. She wants him to take her to dinner. She says it is because he is ashamed to be seen with her. He says the magazine made a hero out of a scientist. He says he likes his life and is not going to change it for her. She says she is emotional and jealous, and she leaves.
They are dressed, and she sits on the counter and offers Sam coffee. He kisses her. They hear a car horn, and she says it is George back from the market. Slob carries in a box of sea-shells. Slob brings in the supplies, and George says they are closing up. Sam tells Kotty that after work he needs to relieve his tension with his hobby of sea-shells. She goes out, and he sits down with the shells. Slob hides money inside of a fake book. George and he talk about money. Sam says many things cannot be written down on paper. Sam says he can call the US President and speak to him as long as he wants. Slob says Sam has a weakness in the tomato. Sam says she is attractive. Slob says he wants to get even with her. Sam gets rough and tells him to forget her. Sam leaves with the book. Claude Dillon (Frank De Kova) comes in, and Slob says he told him not to come there. Sam explains to Dillon that his friend Max committed suicide. Dillon says he woke up and felt drugged. Dillon says he will not rationalize his guilt anymore. Dillon says two men disappeared, but their bodies were not found. Kotty opens a door and listens to them talking. Dillon is pleading with Sam. He tells him to go, and they will discuss it in the morning. Dillon collapses, and Sam realizes that Slob killed him.
Sam calls on Kotty and says her message sounded urgent. She asks why she has to swear loyalty to the United States to get a job. He says the job has a pension. She says she looked up the word “traitor,” and she reads the definition. She says she heard Slob call her a traitor. Sam says that Dillon was drunk. She asks why he got mixed up with Slob. She asks Sam if he is a traitor and tells him to get out. He closes the door and threatens to kill her if she tells anyone about this.
Slob makes friends with Kotty, and he offers to buy her something. She says she is not going steady with the professor anymore. Slob says he made some bucks off Sam for shells. Kotty tells Slob to keep his hands off her. She tastes the soup, and he asks her if she likes him. He tries to kiss her, and she kicks him.
Kotty drinks coffee, and George gives her donuts. She says she told Sam she does not want to see him again. George offers himself to her and says he would like to marry her. She says she loves him like his mother does. She says she would marry him if he wants her to. Eddie comes in with boxes. Eddie and George put fins on their feet. Then they put on goggles with a snorkel.
The two men in uniforms look for something hidden, and they talk to a man outside by radio. He warns them that Slob is going to the kitchen. Then he says they have more time. Behind the counter Slob eats chicken as he and Kotty watch George and Eddie pretending to be skin-diving. Kotty at the clothesline sees the two men climb out of a window. George tells Slob to clean the place up. The two men come in and sit at the counter. Kotty comes back and orders two burgers for the two men. They shows the news article about the murder of Dillon with a knife. Kotty tells Slob that he knew Dillon. Perch comes in with fish in a basket. Slob whispers to Perch that they found Dillon. Perch tells George that he owes him eight, and he leaves. Kotty tells the two men that they take an interest in things around there. They ask what she means, and she tells them to figure it out. Eddie says goodnight and leaves too. Kotty turns out the light and plays the jukebox. She makes a phone call, and Slob cuts off the music. He tells her to finish the dishes. She plugs the jukebox back in.
Perch is driving a truck in the rain and goes by the two men. Kotty talks to Slob about Dillon and says he knew him. She says she saw the two men in his room. Slob checks his room. She says she knows about them and their secret meetings. Alone Slob makes a phone call, and Perch answers. Slob tells him to get the boat ready to go to Mexico. He says the two men were in his room and must be federal men. Slob says he will be waiting on the shore for his dingy. Slob finds a door locked and gets a knife to pry it open. Kotty tells him to get out. He grabs her blouse and orders her to talk. She tries to run out, and he stops her. He asks her what she knows. She knows he will hang. He asks what the professor told her. He throws her against the window that breaks, and then he chokes her. He hears Sam calling, “Open up.” Slob puts on a jacket and opens the door. Sam comes in and says it is a flash flood, and 101 is blocked. He takes off his coat and sits down. Slob asks Sam if he wants to meet Mr. Gregory. Sam says he will phone in sick. He goes to make a call, and Slob grabs him and hits him in the stomach. Sam collapses. Kotty comes in, and Slob says he hated to do it. Slob says Sam knew they were from Intelligence. Slob says they can work together, and Kotty embraces Sam. Slob pulls a gun and plans to take Sam to Mexico. George comes in, and Slob shoots him. Sam says Slob is Mr. Gregory. Sam wraps cloth around George’s wounded arm. Slob says the leaders are not apes. Slob orders George to go into a room. At the door George tells Eddie to get police, but Eddie comes in. George comes back. Eddie sneaks behind the counter. George suggests that Eddie could use a harpoon. Eddie loads the harpoon gun.
A boat arrives on the beach, and the two men see it. They shoot, and Perch kills one of them. The other wounds Perch. Slob sees Perch come in, Perch says they know. Slob shoots at the other man and runs out; but Eddie shoots him with the harpoon gun. Sam kisses Kotty. George puts up a sign “Cook wanted,” sees them kissing and puts up “Waitress wanted.”
This obscure film noir leaves many secrets in the shadows, but the personal feelings between the employees and customers at the diner are more apparent. The intrigue underneath has to do with research that is top secret and so deadly that some have guilty feelings about doing it while others are trying to make money by discovering the secrets. The drama that turns deadly reflects the hidden dangers of the Cold War.