Set against the backdrop of the Cold War and Soviet political repression of the early 1980s prior to perestroika, Moscow on the Hudson tells the story of Vladimir Ivanoff (Robin Williams), a saxophonist with the Moscow circus.The story begins in New York with Vladimir advising a newly arrived Frenchman that he is on the wrong New York bus and giving him instructions on how to get to his destination. He then tells the Frenchman that it is always difficult getting around the city when one first arrives. Vladimir then begins remembering his own arrival to New York from Russia, and the scene shifts to Vladimir riding on a Russian bus some time earlier.Vladimir exits the bus and immediately witnesses a group of three people holding signs being accosted by two men, likely KGB agents or secret police, who force them into a nearby car and confiscate their signs. Vladimir then inquires of a passing Russian soldier if the nearby queue is for toilet paper; the soldier replies that it is for shoes. Vladimir joins the queue and obtains three pairs of shoes in the only size (38) now available.Vladimir arrives late to rehearsal at the circus and Boris (Savely Kramarov), one of the apparatchik assigned to the circus, criticizes him harshly and implies that he may miss the approaching trip to New York City. Vladimir tells him the reason he was late and ultimately gives Boris one pair of shoes obtained from the queue.Later, while Vladimir is riding with his friend, circus clown Anatoly Cherkasov (Elya Baskin), in Anatoly's Lada, Anatoly begins expressing his discontent with life in Russia, claiming that he is an oppressed artist. Vladimir expresses disinterest in Anatoly's complaints. Anatoly stops to buy fuel for his car from a mobile black-market gasoline dealer. While the friends wait for the gasoline seller to fill Anatoly's jerrycans, the two practice their English. Anatoly reveals to Vladimir in English that he plans to defect during the upcoming trip to New York. Vladimir is disconcerted that Anatoly has told him this as he is obligated to inform on him. Anatoly shouts in English at the uncomprehending fuel seller and oblivious passing motorists that he wants to see the world.Anatoly leaves Vladimir at another queue; as Vladimir exits the vehicle, Anatoly asks if he will be coming by the apartment at 9:00 p.m. as usual and Vladimir agrees. After inquiring and determining that toilet paper can be purchased at this queue, Vladimir begins to walk to the end of the excessively long line but meets with a neighborhood friend, Leonid, already standing in line. During the ensuing conversation, Leonid reveals that he was once a teacher but is now paving roads after the authorities had sent him to a camp for protesting the war in Afghanistan. Leonid also reveals that the authorities had declared him to be crazy for protesting the war. After agreeing to talk later, Leonid advises Vladimir to never go crazy.Vladimir returns home to his family, who are overjoyed that he has obtained toilet paper. Vladimir announces that he won't be staying for dinner as he is meeting Svetlana. Vladimir's mother expresses a desire for Vladimir to marry Svetlana, and Vladimir remarks that he doesn't want another marriage.Vladimir meets with Svetlana, and they both walk to Anatoly's apartment for their date. Svetlana expresses a desire for Vladimir to join the communist party as it would make obtaining an apartment when they get married easier; Vladimir responds that he is not a "joiner". At the apartment, after Anatoly leaves, Vladimir gives Svetlana a gift -- a roll of toilet paper. Svetlana expresses her jealousy that Vladimir gets to see America without her and hints that she would like Vladimir to obtain designer jeans for her.Vladimir returns home drunk from vodka. In the morning, around the breakfast table, Vladimir's grandfather, Nicholai Ivanoff, aggressively criticizes the news reports on the television and Russia's leaders in general. As Vladimir is leaving the building with packed suitcases for the circus trip to America, he is intercepted by the two circus-assigned apparatchik waiting at the entrance. They question Vladimir about his grandfather's anti-Soviet behavior and imply that he may be senile and need to be committed. Vladimir responds that he is just a comedian, an old man, and a war hero who should just be ignored. They also reveal that they are aware that Vladimir and Svetlana have been using Anatoly's apartment for their "sexual encounters". Both agents finally reveal that they want Vladimir to "keep an eye on" Anatoly Cherkasov during the trip to America in exchange for protecting his grandfather.The Moscow circus arrives in New York and are shuttled around in a chartered bus. The performers are amused at the colorful environment that is New York, which strongly contrasts with the bleak surrounding of Moscow (as portrayed earlier). During the bus ride, Anatoly writes "freedom" in the dust on the bus window, and Vladimir quickly wipes it off.The performers stay at the Howard Johnson Hotel, and Vladimir and Anatoly happen to be sharing a room. Vladimir revels in the American custom of taking the towels, which he packs into his suitcase, and the quality of the toilet paper. Vladimir reveals to Anatoly that it is no coincidence they are sharing a room together because the apparatchik watching over the circus want him to "spy on" Anatoly.During a formal reception, Anatoly reveals to Vladimir that he intends to defect during the opening parade and his opening bicycle routine; Vladimir remarks, "Good. They grab you and throw you right to bear". Vladimir and Anatoly enter a bathroom, and the two Apparatchik, who have been shadowing Anatoly throughout the evening, emerge from the same toilet stall just as Anatoly was about to comment on his plans. The Apparatchik comment that they will soon be back in Moscow, but otherwise all leave the bathroom without further drama.The next day during the opening circus performance, Anatoly attempts to defect but is met by the Apparatchik agents.The following day, the performers are allowed to shop at Bloomingdale's for 30 minutes before going to the airport to return to Russia. Vladimir meets a perfume clerk at Bloomingdale's, Lucia Lomardo (María Conchita Alonso), while attempting to find blue jeans for Svetlana. Anatoly once more reveals to Vladimir that he is going to defect in Bloomingdale's. Vladimir angrily challenges Anatoly to just do it and stop informing him of the plan. However, Anatoly is shadowed by the quieter of the Apparatchik and loses his nerve.As the performers are being led back to the bus, Vladimir attempts to buy the designer jeans for Svetlana. Anatoly seemingly dares Vladimir to defect in his stead. Vladimir then attempts to defect to one of Bloomingdale's security guards, Lionel Witherspoon (Cleavant Derricks). A clerk announces the defection, and the Apparatchik, who are distracted by their own shopping, rush over to prevent it. A chase ensues through Bloomingdale's, out onto the street, and back into Bloomingdale's. Vladimir then attempts to hide behind Lucia's counter. Orlando Ramirez (Alejandro Rey), an immigration lawyer, approaches and gives Lucia his card to give to Vladimir. After trying to hide inside Lucia's dress, Vladimir crawls away through Bloomingdale's but once again encounters Lionel. Boris and the other Apparatchik arrive and confront Vladimir, but Lionel defends him. Boris first pleads with Vladimir to return and then threatens, but Vladimir repeats, "I defect", to the cheers of the rapidly assembling crowd. Connie Chung and an ABC News crew are already on scene. The FBI arrive and interview Vladimir about why he is defecting and whether or not he has relatives or friends in America. Lionel, basking in the glare of the media, offers to take in Vladimir after revealing he knows no one in America outside of Lionel and Lucia. As a final parting gesture, Vladimir rushes out onto the street as the charted bus of circus performers is leaving and says goodbye to his saxophone, which had been left on the bus. He also communicates to Anatoly that he is now free (a free bird).Lionel Witherspoon (Cleavant Derricks), an African American security guard who has just protected Vladimir from his furious Russian handlers during Vladimir's defection at Bloomingdale's, takes him home to Harlem to live with Lionel's mother, unemployed father, sister, and cranky but good-hearted grandfather--a living arrangement noticeably similar to that of Vladimir's family back in Moscow.With the help of sympathetic immigration attorney Orlando Ramirez (Alejandro Rey), a naturalized citizen from Cuba who witnessed Vladimir's defection, Vladimir soon adapts to life in America. Vladimir attempts to find work despite speaking little English and fearing the threat of his former KGB handlers. He initially lives in poor neighborhoods and takes low-paying jobs such as fast-food service, limousine driver, and sidewalk merchant.Vladimir starts a relationship with Lucia. At a party celebrating Lucia's becoming an American citizen, Vladimir proposes to her; but she refuses and breaks up with him. A little while later, Lionel decides to move to Alabama to be with his young son; and Vladimir learns from a friend of his sister that his beloved grandfather back home in Moscow has died.Grieving, Vladimir goes to a Russian nightclub to ease his mind. When he returns home, late to his apartment building and drunk, he is mugged by two young men. He later reports the incident to the police with Orlando present, and the two go to a diner where Vladimir rants about his misfortunes. A nearby Russian immigrant overhears the conversation, and interrupts Vladimir to disagree, leading the two into a tense confrontation that is settled after Vladimir comes to appreciate his good fortune of living in America. Soon after, Lucia reunites with Vladimir telling him that she is not ready for marriage but would love to live with an immigrant, and Lionel moves back from Alabama and takes over Vladimir's job driving a limousine.In the end, Vladimir gets a job as a saxophonist in the band at the Russian nightclub, with time to play the music he loves during the day. He encounters the former apparatchik Boris operating a hot dog stand. (Boris had lost his status back in the Soviet Union after Vladimir's defection.) The former apparatchik is glad to see Vladimir and gives him a free hot dog, showing his appreciation for the life he too now has in America.