At the Roseland Ballroom in New York City, Cleo teaches dance lessons to elderly patrons who wish to recapture the glory and romance of their youth. One regular, a widow named May, is obsessed with her deceased husband, Eddie, who loved the waltz. When a ladies’ man named Stan leads May onto the dance floor, she envisions a younger version of herself in a mirror, dancing with Eddie. May tries to replicate the apparition with another partner, the master of ceremonies, but realizes that she can only experience her fantasy with Stan. Despite May’s aversion to alcohol, she meets Stan at the bar and he guides her back to the dance floor, where she sees a younger version of herself with Eddie in the mirror yet again. Later, at a Roseland dance contest, Cleo points out a couple that was “made for each other” and May wishes to see herself again in the mirror. When she partners with Stan on the dance floor and points to their image, he claims it is an optical illusion. Astonished that Stan is able to share her vision, May later approaches him at the Roseland bar, but Stan evades her attention, noting that her partner in the mirror is not him, but Eddie. May agrees to have a drink. As time goes by, Stan becomes more intrigued by May and she becomes increasingly peculiar, drinking and staring into mirrors. When Stan asks May to dance, she declines, claiming that Stan is an inferior replacement for Eddie, but she changes her mind with the conviction that her visions are psychic messages of approval from Eddie. Stan wishes to be recognized as his own person, not a manifestation of Eddie, and shares his life story with May, admitting that he spent years mourning the death of his young bride. Although the band plays a salsa, not a waltz, May asks Stan to dance. At another Roseland event, a young gentleman named Russel celebrates the birthday of his older lover, Pauline. He dances with Pauline’s friend, Marilyn, while Pauline tells Cleo that Marilyn was recently abandoned by her husband. When Russel returns to the table and takes Pauline to the dance floor, Marilyn tries to slip away unnoticed. However, Marilyn realizes she does not have a coat check token and Russel corners her, asking for another dance. He takes her to Cleo’s darkened backstage studio, explaining that Cleo was his dance teacher, and brandishes the coat check token. Russel encourages Marilyn to look for a new relationship, but she is intent on finding a job so she can be independent. As Russel proposes a dance with Marilyn, Cleo turns on the lights and leads the couple out of her studio. Sometime later, Cleo trains a young couple for an upcoming hustle contest as Russel watches. He then phones Marilyn, declaring his desire to start a relationship, but she is preoccupied with a pending job interview. Back at the studio, Russel sees Pauline, who demands affection from her protégé and decorates him with a new silk scarf. Pauline invites Russel to her apartment but he declines, claiming he must look for a job. Pauline argues that she is unwell and needs his care. Later, Russel escorts Marilyn to the Roseland bar, insisting that Pauline wants him to “look after” her, too. He orders drinks and charges them to Pauline’s tab, then notices Cleo eyeing him and asks Marilyn to dance. Cleo follows with another partner and pulls Russel away, but he leaves her to go after Marilyn. Waiting for the bus, Marilyn regrets her solitude and Russel escorts her back to Roseland. Sometime later, Russel and Marilyn run into Pauline and Cleo. As Russel and Pauline dance, Cleo reflects that Russel enjoys being a gigolo, but Marilyn argues that Russel wants to detach himself from Pauline and support himself as a professional dancer. Just then, Russel appears with Pauline, who is doubled over in pain, and Marilyn guides the couple to a cab. Back at Cleo’s studio, Russel reports that Pauline is convalescing in the hospital. When Cleo proposes that Russel partner with her for a professional career, Russel leaves for a Roseland date with Marilyn. However, he arrives late and Marilyn complains about his dependency on Pauline. She explains that she loves her new job, and will soon make enough money to support them both. Later, in the ballroom, the friends celebrate Pauline’s homecoming and she insists that Russel dance with Marilyn. The couple goes to Cleo’s studio, instead, where Marilyn agrees to pay for Russel’s training with Cleo, but Russel is reticent about announcing their relationship. Meanwhile, on the dance floor, Cleo’s students unsuccessfully compete in the hustle contest. When Russel and Marilyn return to their table, Pauline presents Russel with an expensive watch and tickets for a tropical cruise. As Cleo consoles the hustle contestants, Marilyn leaves Roseland for good. On another day at the ballroom, an elderly woman named Rosa collapses in exhaustion on the ladies’ lounge sofa. She tells the attendant about her deceased dance partner, Arthur, who would embarrass her by napping spontaneously. Rosa remembers an evening when she and Arthur danced in a Peabody contest. Another couple won, but Bert, the male partner, passed out as he accepted the trophy. Rosa and Arthur continued to train, but Arthur was unambitious and refused to smile during their routines. One night, Arthur arrived late to another Peabody contest and consoled Rosa by asking her to perform her Marlene Dietrich impression. When she expressed regret that she was unable to pursue her dream of becoming an opera singer, Arthur proposed marriage. Back in the lounge, Rosa tells the attendant that Arthur continued to propose, but they never saw each other outside Roseland. Rosa insists that she doesn’t miss Arthur and claims that dancing alone enables her to fantasize about her ideal partner. However, she remembers one evening when Arthur collapsed in the men’s lounge but wanted to dance anyway. Rosa feigned exhaustion to prevent Arthur from dancing and they watched the contest from the sidelines, agreeing that they would have won that night because of the inferior competition. Arthur stole a kiss from Rosa before leaving Roseland, but fell into a coma on the subway. Back at the Roseland ladies’ lounge, Rosa hears the orchestra play the Peabody and heads to the dance floor with excitement, but she turns away, realizing she is missing her partner. As Rosa looks out at New York City from the Roseland foyer, she wishes aloud to never leave the ballroom again and the master of ceremonies asks her to dance. On the dance floor, Rosa spins with delight and collapses in death, still fantasizing about her ideal partner.