Chu Chu Ramírez, an itinerant Mexican farm laborer, is proud of his new American citizenship and treasures a letter he received from the President in response to one Chu Chu wrote to him. While Chu Chu's cousin, Manuel Ramírez, and friends, Celestino Garcia and Willie Chung, spend their last pay from the California grape season on gambling and women, Chu Chu, determined to improve his situation, buys clothes and an encyclopedia. Soon an employment agency arranges an interview for him with farmer Ansel Ames and his wife Elena. Although Mrs. Ames regards Chu Chu as "another foreigner," Ames gives him a month's work clearing land. After a week, Mrs. Ames, who no longer loves her husband, shows interest in the virile, young Chu Chu. When she apologizes to him for her remark about him being another foreigner, she explains that she does not like having "a dirty rag head or a chink around," to which Chu Chu adds, "or a greaser like Chu Chu Ramírez." Mrs. Ames states that she did not mean to imply a dislike for him but tells him that he has one thing in common with all Mexicans, "he sure can look mean." One night, Chu Chu dresses up and goes to a bar in town and meets Nancy, who has come north from Sacramento looking for a job. Chu Chu helps get her car started and drives her back to Sacramento, where he puts up his letter from the President as collateral for some cash which he then gives to Nancy. One night, just before Chu Chu is due to finish his job, Mrs. Ames tries to seduce him but he sends her away. Later, in Sacramento, when Chu Chu goes to cash his pay check, the bank refuses payment. Chu Chu again encounters Nancy, who, intoxicated, speaks of her marriage to a test pilot who was killed in a crash. He takes her back to the cheap motel in which she is living, and although she tells him he should not waste his time on a "wino," he asks her to be his girl. When Chu Chu tells Ames that his check is no good, Ames accuses him of trespassing and threatens him with a shotgun. Chu Chu then brings Ames before a labor conciliation board and is promised his pay within sixty days. After the judgment, Nancy tells Chu Chu that she is leaving Sacramento for Los Angeles, but he says he will follow, bring her back and marry her. Two months later, when Chu Chu goes to the Ames farm to get his pay, Ames tries to attack him, but Chu Chu knocks him down. After Chu Chu leaves, Mrs. Ames tells her husband that Chu Chu is worth ten of him. Ames hits her, and when he pushes her against a shotgun rack, one gun falls and shoots him in the shoulder. Meanwhile, Chu Chu learns that Nancy is sick in Los Angeles and prepares to go to her, but is arrested for shooting Ames. After Manuel visits Chu Chu in jail and tells him that Nancy has attempted suicide by gassing herself, Chu Chu escapes, and although handcuffed, jumps on a freight train and breaks the handcuffs on one of the train's wheels. He finds Nancy quite ill, working in a dance hall, and while they are dancing he is arrested by plainclothesmen who have staked out the hall. At his trial, both Mr. and Mrs. Ames testifies that Chu Chu shot Ames, while Chu Chu's friends speak on his behalf. The jury finds that Chu Chu did assault Ames with a deadly weapon, but requests a light sentence due to the provocation he endured. Before he is sentenced, Chu Chu asks to read from another letter he has written to the President stating that as a convict he will no longer be a citizen, something that would be worse than death to him. Taking the jury's words and Chu Chu's letter into consideration, the judge sentences Chu Chu to a year and a day. Afterward, Chu Chu's friends begin to haunt the Ames farm in an attempt to pressure them into confessing the truth. When Nancy, still very ill, collapses at the farm after accusing Ames of destroying Chu Chu, Manuel and the others take her to a hospital. Mrs. Ames then tries to reconcile with her husband and says that they should get Chu Chu released from jail even though they will be charged with perjury. Realizing that they must now do the right thing, to save themselves as well as Chu Chu, they embrace, and their confession frees Chu Chu. When he visits Nancy in the hospital, she still wants him to forget her but he refuses to leave her and tells her she must get well for him. Finally, she agrees.