One morning in New York, Charlie Samson heads to work, still reeling from the news that his wife Helen is pregnant. Charlie works all day as a bookkeeper and at night attends school to become an accountant, a profession he loves, and worries that he has neither time nor money enough to start a family. On the subway, Charlie’s work friend Ken, unaware that Helen is pregnant, discusses the difficulties of supporting his wife and children, and later the two watch enviously as a young man befriends an attractive female. They arrive at the office to find Walter, a slightly older coworker, already there, and the three agree that none will join the bachelor party being thrown that night for work friend Arnold. Soon after, however, Eddie Watkins, who is throwing the party, arrives and places a series of calls to his girl friends, winning the other men’s admiration and prompting each in turn to decide to join the party that evening. The evening begins at a restaurant, and after several rounds of drinks and the presentation of gag gifts, the party is well on its way. Meanwhile, Charlie’s sister Julie visits Helen, and when Helen worries that Charlie is not excited about the baby, Julie reveals that her husband of eleven years is having an affair, one of many. The men then leave the bar and wander the streets of Greenwich Village, where a drunken Charlie flirts with a pretty beatnik woman who invites him to join her later at a party. The men go to Eddie’s apartment to watch stag films, and consequently ignore Arnold when he tries to talk about his bafflement at how he wound up engaged. Although they are all tired and dull when the movies end, no one wants to go home, so instead they head to a bar. At home, Julie horrifies Helen with her suggestion that she “get rid of” the baby in order to protect her marriage. When Charlie calls to say he will be late, Helen asks him to come home, but he responds with anger. In the men’s room, Charlie vents his anger to Ken, declaring that he can no longer work and study constantly and wondering what the point is of working so hard and never having fun. Ken responds that he once, while unemployed, drank and caroused too much and nearly ruined his marriage, which was never the same afterward. Seeing Charlie’s confusion and frustration, Ken encourages him to stick to his plan to better himself, and urges him to go home before the activity becomes too wild. Charlie remains unconvinced, however, and instead of leaving with Ken, accompanies the rest of the group to a striptease bar, where Arnold confides in Charlie that he is a virgin and afraid he will not be able to satisfy his fiancée. Unsure of how to respond and questioning his own marriage, Charlie remains silent, but later, when Eddie goads Arnold into visiting a prostitute, Charlie agrees to accompany him for moral support. In the prostitute's bedroom, Arnold grows frightened and runs out, supported by Charlie, who calls it a barbaric custom. They join Eddie and a drunken Walter at a nearby bar, and when Eddie tries to convince them to go back to the Greenwich Village party, Charlie quotes what Ken said earlier about the dangers of infidelity, and the two nearly come to blows. Although Eddie is angry, his reluctance to be alone overcomes him and he wheedles the others into taking the subway to Charlie’s to get more money to go to another bar. On the way, Walter reveals that he has been diagnosed with asthma that will prove fatal if he does not move out of the city, and when Charlie urges him to quit and move, Walter responds with drunken fury that he has a family to support and is too old to find a new job. After calling life a joke, “a lot of noise about nothing,” Walter exits the subway train alone, ignoring Charlie’s calls to him. Charlie decides to stay at home and goes upstairs to get some cash to lend Eddie. There, he tells Helen he is quitting school, after which she offers to get rid of the baby, but is shocked when he considers the possibility. She angrily pushes him away, so Charlie rejoins his buddies and they return to the Greenwich Village party, where the beatnik tells Charlie she will kiss him as long as he tells her he loves her, whether he means it or not. Saddened, he escorts Eddie and a highly intoxicated Arnold to a bar, where Arnold, ignored by the others, calls his fiancée and cancels the wedding, then collapses. Charlie plans to bring him home, and when Eddie cajoles him to stay out, Charlie realizes that Eddie will stop at nothing to avoid being alone. At Arnold’s, the groom hears his fiancée inside talking with his parents and confesses to Charlie that he called off the wedding because he is terrified that he will not be a good enough husband. As Charlie advises Arnold to tell his girl the truth and count on her understanding, he realizes how much he loves and misses Helen, and how empty a life without her would be. He rushes home to tell her he loves her, and as the sun rises, they embrace.