In the early 1910s, Chico works in the sewers of
Paris. He expresses his desire to be a street sweeper, to work above ground, and light candles at a nearby church. After a meeting with the church's priest, Chico receives the recommendation he needs for the street-sweeping job. Diane is a young prostitute living with her abusive sister, Nana. When news arrives that their uncle and aunt have returned with a fortune, Nana particularly hopes they will provide more comfortable accommodations. But when the uncle asks Diane directly whether she and her sister have kept "clean and decent", the look on her face confirms his worst suspicions and, refusing to take them home, disowns them. Nana, furious at Diane for revealing the truth, begins to beat her. As Diane tries to escape on the street, Chico steps in to rescue her. Following a brief flirtation between Diane and Chico, Nana returns with the police, intending to arrest Diane. Once again, Chico intervenes, asserting that Diane is not a prostitute but his wife. Despite initial skepticism, the police refrain from arresting Diane but ask for Chico's address to verify the marriage. Concerned about potential repercussions for lying, Chico fears losing his job as a streetsweeper. To provide an alibi, he suggests Diane move in with him. After ensuring she's not being exploited, Diane agrees to Chico's proposal. Soon afterwards, the police visit Chico's apartment for further investigation, and their strategy succeeds, absolving them both of suspicion. With no more reason to stay, Diane prepares to leave, feeling disheartened after having grown fond of Chico and his airy sixth-floor walkup flat. When Chico offers her to stay, she joyfully accepts, feeling that Chico is a godsend. As they spend more time together, they quickly fall in love and decide to marry genuinely. News of
World War I reaching France arrives, prompting the couple to hold an unofficial wedding in their apartment, with God as their sole witness. Chico is swiftly recruited, forcing him to depart for the battlefield. Upon his departure, a resentful Nana returns, deriding Diane for her marriage and attempting to assault her once more, only to be forced out by Diane fighting back with newfound bravery thanks to Chico's support. While Chico fights in the war, Diane finds work at a munitions factory. During a battle, Chico is gravely wounded and believes he's dying. When Diane is told that Chico has been officially declared dead, she is devastated. Yet once the war ends, Chico returns home, his death having been wrongly reported, but he is now blind. ==Cast==